List of journal publications

[118]. Y. Efendiev, J. Galvis, R. Lazarov, J. Willems, Robust Solvers for Symmetric Positive Definite Operators and Weighted Poincare Inequalities, accepted in Lecture Notes in Computer Science (Proc. 8-th Conference on Large Scale Scientific Computation), 2011 (available also as Technical Report ISC-Preprint-2011-03, Texas A& M University).

[117]. P. Chatzipantelidis, R. Lazarov, and V. Thomee, Some error estimates for the lumped mass finite element method for a parabolic problem, Mathematics of Computation, 81 (277), (2012), 1-20 (also available as Technical Report ISC-10-03-MATH , Texas A& M University).

[116]. O.P. Iliev, R.D. Lazarov, and J. Willems, Variational Multiscale Finite Element Method for Flows in Highly Porous Media, (also available as IAMCS Preprint 2011-172) SIAM Multiscale Model. Simul. 9 (4) , (2011) 1350-1372

[115]. C.C. Douglas, Y. Efendiev, R.E. Ewing, V. Ginting, R.D. Lazarov, M.J. Cole, G. Jones, Least-squares approach for data recovery in dynamic data-driven applications simulations, J. Computing and Visualization in Science 13 (8), (2010), 365 -- 375, DOI: 10.1007/s00791-011-0154-8

[114].O.P. Iliev, R.D. Lazarov, and J. Willems, Discontinuous Galerkin Subgrid Finite Element Method for Approximation of Heterogeneous Brinkman's Equations, Lecture Notes in Computer Science, vol. 5910, I. Lirkov, S. Margenov, and J. Wasniewski (Eds.), pp. 14--25, Springer, Heidelberg, (2010)

[113]. O.P. Iliev, R.D. Lazarov, and J. Willems, Fast Numerical Upscaling of Heat Equation for Fibrous Materials, J.Computing and Visualization in Science, 13 (6), (2010), 275 -- 285 (DOI: 10.1007/s00791-010-0144-2)

[112]. R.K. Sinha, R.E. Ewing, and R.D. Lazarov, Mixed Finite Element Approximations of Parabolic Integro-Differential Equations with Nonsmooth Initial Data, SIAM J. Numer. Anal., 47 (5) (2009), 3269 -- 3292. (DOI 10.1137/080740490)

[111]. R.E. Ewing, O.P. Iliev, R.D. Lazarov, I. Rybak, and J. Willems, A simplified method for upscaling composite materials with high contrast of the conductivity, SIAM J. Scientific Computing, 31 (4) (2009), 2568--2586.

[110]. R. Lazarov, S. Repin, and S. Tomar, Functional a posteriori error estimates for discontinuous Galerkin approximations of elliptic problems, J. Numerical Methods for PDEs, 25 (4) (2009), 952--971. (DOI: 10.1002/num.20386)

[109]. B. Cockburn, J. Gopalakrishnan, and R. Lazarov, Unified hybridization of discontinuous Galerkin, mixed, and conforming methods for second-order elliptic problems, SIAM J. Numer. Anal., 47 (2), (2009), 1319--1365. (DOI: 10.1137/070706616)

[108]. P. Chatzipantelidis, R. Lazarov, and V. Tomee, Parabolic finite volume element equations in nonconvex polygonal domains, Numer. Methods for Partial Diff. Equations, 25 (3) (2009), 507--525. (DOI: 10.1002/num.20351)

[107]. O. Iliev, R. Lazarov, J. Willems, Numerical study of two-grid preconditioners for 1-D elliptic problems with highly oscillating discontinuous coefficients, Computational Methods in Applied Mathematics, 7 (1) (2007), 48--67.

[106]. K. Kachiashvili, D. Gordeziani, R. Lazarov and D. Melikdzhanian, Modeling and simulation of pollutants transport in rivers, Applied Mathematical Modelling, 31 (7) (2007), 1371--1396.

[105]. R.D. Lazarov, S. Lu, and S.V. Pereverzyev, On the balancing principle for some problems of numerical analysis, Numerische Mathematik, 23 (4) (2007), 659--689 (also as RICAM Techinical Report #25 )

[104]. R.D. Lazarov and S.D. Margenov, CBS constants for graph-Laplacians and application to multilevel methods for discontinuous Galerkin systems, Joural of Complexity, 23 (4-6) (2007), 498--515 (also as RICAM Techinical Report #28 ).

[103]. R.E. Ewing, O.P. Iliev, R.D. Lazarov, and A. Naumovich, On convergence of certain finite volume difference discretizations for 1-D poroelasticity interface problems, On convergence of certain finite volume difference discretizations for 1-D poroelasticity interface problems, Numer. Methods for Partial Differential Equations, 23 (3) (2007), 652-671.

[102]. R.D. Lazarov and X. Ye, Stabilized discontinuous finite element approximations for Stokes equations, J. Comput. Appl. Math. , 198 (1) (2007), 236--252. # MR2250399

[101]. V.A. Dobrev, R.D. Lazarov, P.S. Vassilevski, and L.T. Zikatanov, Two-level preconditioning of discontinuous Galerkin approximations of second order elliptic equations, Numer. Linear Algebra Appl., 13 (9) (2006), 753--770 # MR2269798

[100]. P. Chatzipantelidis, R.D. Lazarov, V. Thomee, and L. Wahlbin, Parabolic finite element equations in convex polygonal domains, , BIT Numerical Mathematics. , 43 (Suppl. 1) 2006, S113-S143. # MR2269798

[99]. R.D. Lazarov and L.T. Zikatanov, An exponential fitting scheme for general convection-diffusion equations on tetrahedral meshes, Technical Report ISC-04-15-MATH , Texas A& M University, Comput. Appl. Math., (Obchysljuval'na ta prykladna matematyka, Kiev), 1 (92) (2005), 60-69.

[98]. C.C. Douglas, Y. Efendiev, R.E. Ewing, V. Ginting, R.D. Lazarov, M.J. Cole, G. Jones, Least-squares approach for data recovery in dynamic data-driven applications simulations, submitted to Journal of Computing and Visualization in Science

[97]. A. Kurganov, R. Lazarov, D. Levy, G. Petrova, and B. Popov, Eitan Tadmor - 50, Comput. Meth. Appl. Math. , 4 (3) (2004), 265 -- 270.

[96]. A .B. Andreev, R.D. Lazarov, and M.R. Racheva, Postprocessing and Higher Order Convergence of Mixed Finite Element Approximations of Biharmonic Eigenvalue Problems, J. Comput. Appl. Math. , 182 (2) (2005) 333 -- 349 (also Technical Report ISC-04-04-MATH , Texas A& M University) # MR2147872 (2006d:65127)

[95]. P. Chatzipantelidis, V. Ginting, and R.D. Lazarov, A finite volume element method for nonlinear elliptic problems, Numer. Linear Algebra Appl. , 12 (2005) 515 -- 546 (also Technical Report ISC-04-06-MATH , Texas A& M University), # MR2150166 (2006f:65115)

[94]. V. Ginting, R. Ewing, Y. Efendiev, and R. Lazarov, Upscaled modeling for multiphase flow, Comput. Appl. Math. , 23 (2-3) , (2004) 213 -- 233 (also Technical Report ISC-03-05-MATH , Texas A& M University) # MR2146982 (2005m:76167)

[93]. P. Chatzipantelidis and R.D. Lazarov, Error estimates for finite volume element method for elliptic PDE's in nonconvex polygonal domains SIAM J. Numer.Anal. , 42 (5) (2005) 1932 -- 1958 (also Technical Report ISC-03-04-MATH , Texas A& M University) # MR2139231 (2006f:65108)

[92]. P. Chatzipantelidis, R. Lazarov, and V. Thomee, Error estimates for the finite folume element method for parabolic equations in nonconvex polygonal domains Numer. Methods for Partial Diff. Equations , 20 (5) (2004), 650 - 674. # MR2076342 (2005g:65122)

[91]. C. Carstensen, R.D. Lazarov, and S. Tomov, Explicit and averaging a posteriori error estimates for adaptive finite volume methods, SIAM J. Numer.Anal. , 42 (6) (2005) 2496 -- 2521 (also as Isaac Newton Institute for Mathematical Sciences, (2003), Cambridge University, UK) # MR2139403 (2006b:65165)

[90]. R.D. Lazarov, J.E. Pasciak, J. Schoberl, and P.S. Vassilevski, Almost optimal interior penalty discontinuous approximation of symmetric elliptic problems on non-matching grids, Numerische Mathematik , 96 (2) , (2003) 295--315. # MR2021492 (2004j:65205)

[89]. R.D. Lazarov and S.Z. Tomov, A posteriori error estimates for finite volume element approximations of convection-diffusion-reaction equations, Technical Report ISC-00-02-MATH, Texas A& M University, Computational Geoscienes, 6 (3-4) (2002) 483 - 503. # MR1956027 (2004b:65166)

[88]. R.E. Ewing, A. Ibragimov, and R.D. Lazarov, Domain decomposition algorithm and analytical simulation of coupled flow in reservoir/well system, J. Korea SIAM , 5 (2) (2001), 71-99.

[87]. R.D. Lazarov, S.Z. Tomov, and P.S. Vassilevski, Interior penalty discontinuous approximations of elliptic problems, Technical Report ISC-00-04-MATH, Texas A& M University, Comput. Methods Appl. Math., 1 (4) (2001), 367-382

[86]. C. Kim, R.D. Lazarov, J.E. Pasciak, and P.S. Vassilevski, Multiplier spaces for the mortar finite element method in three dimensions, SAM Numer. Anal. , 39 (2) (2001), 519-538 (also as Technical Report ISC-00-07-MATH, Texas A& M University). # MR1860265 (2002g:65143)

[85]. R.D. Lazarov, J.E. Pasciak and P.S. Vassilevski, Iterative solution of a conbined mixed and standard Galerkin discretization method for elliptic problems, Technical Report, ISC-99-03-MATH, Texas A& M University Numer. Linear Algebra Appl., 8 (2001), 13-31.

[84]. J. Bramble, R. Lazarov, and J. Pasciak, Least-squares methods for linear elasticity based on a discrete minus one inner product, Technical Report ISC-99-05-MATH, Texas A&M University , Computer Meth. Appl. Mech. Engrg., 191 (2001) 727--744. # MR1870517 (2002i:65123)

[83]. R.E. Ewing, O.P. Iliev, and R.D. Lazarov, A modified finite volume approximation of second-order elliptic equations with discontinuous coefficients, Technical Report, ISC-99-01-MATH, Texas A& M University SIAM Sci. Comput., 23 (4) (2001), 1334--1350. # MR1885604 (2003c:65104)

[82]. R. Ewing, R. Lazarov, T. Lin, and Y. Lin, Mortar finite volume element approximations of second order elliptic problems, Technical Report ISC-99-08-MATH, Texas A&M University , East-West J. Numer. Math., v. 8 (2000), 168-183.

[81]. R.E. Ewing, R.D. Lazarov, and Y. Lin, Finite volume element approximations of non-local reactive flows in porous media, Technical Report ISC-98-07-MATH, Texas A& M University, Numerical Methods for PDEs, v. 16 (2000), pp. 285--311.

[80]. R.E. Ewing, R.D. Lazarov, and Y. Lin, Finite volume element approximations of non-local in time one-dimensional reactive flows in porous media, Technical Report ISC-98-06-MATH, Texas A& M University, Computing, v. 64 (2000) pp. 157--182.

[79. R.E. Ewing, R.D. Lazarov, S.L. Lyons, D. Papavassiliou, and J.E, Pasciak, Numerical Well Model fof Non-Darcy Flow, Computational Geosciences, v.3 (1999), 185--204.

[78]. R.D. Lazarov, L. Tobiska, and P. Vassilevski, Stream-line diffusion least-squares mixed finite element methods for convection-diffusion problems, East-West J. of Numerical Mathematics, v. 5 (1997), No.4, pp. 321-335.

[77]. J. Bramble, R. Lazarov, and J. Pasciak, Least-squares for second order elliptic problems, Comput. Meth. Appl. Mech. Engn., v. 152 (1998), Nos.1-2, pp. 195-210.

[76]. H.S. Chen and R.D. Lazarov, Domain splitting algorithm for mixed finite element approximations to parabolic problems, East-West J. of Numerical Mathematics, v. 4 (1996), 121-135.

[75]. H.S. Chen, R.E.Ewing, and R.D. Lazarov, Superconvergence of the mixed finite element methods for parabolic problems with nonsmooth initial data, Technical Report ISC_08-94-MATH, Texas A&M University, Numer. Mathematik, v. 78 (1998), 495-521.

[74]. Z. Chen, R. Ewing, R. Lazarov, Yu. Kuznetsov, and S. Maliassov, Multilevel preconditioners for mixed methods for second order elliptic problems, Numer. Lin. Alg. Appl., 3 (5) (1996), 427 - 453.

[73]. R.D. Lazarov and P.S. Vassilevski, Preconditioning saddle-point problems arising from mixed finite element discretizations of elliptic equations, Numer. Lin. Algebra Appl., v. 3 (1) (1996), 1 - 20.

[72]. Z. Chen, R. Ewing, and R. Lazarov, Domain decomposition algorithms for mixed methods for second order elliptic problems, Math. Comp., v. 65 (1996), 467 - 490.

[71]. J.H. Bramble, R.D. Lazarov, and J.E. Pasciak, A least-squares approach based on a discrete minus one inner product for first order systems, Math. Comp., 66 (1997), 935 - 955.

[70]. R.D. Lazarov, I.D. Mishev, and P.S. Vassilevski, Finite volume approximation of convection-diffusion problems on grids with local refinement, Computing, v. 53 (1) 1994, 33-57. MR# 95f:65196

[69]. P.S. Vassilevski, S. Petrova, and R.D. Lazarov, Preconditioning elliptic problems on grids with multilevel local refinemnet, Methematica Balkanica, v. 8 (2-3) (1994), 179 - 196.

[68]. R.E. Ewing, R.D. Lazarov, and A. Vassilev, Finite difference schemes for parabolic problems on composite grids with refinement in time and space, SIAM J. Numer. Anal., v. 31 (6) (1994), 1605-1622. MR# 95j:65095

[67]. R.D. Lazarov, I.D. Mishev, and P.S. Vassilevski, Finite volume methods for convection-diffusion problems, SIAM J. Numer. Anal., v. 33 (1) (1996), 31 - 55

[66]. R.E. Ewing and R.D. Lazarov, Approximation of parabolic problems on grids locally refined in time and space, Appl. Numerical Mathematics, v. 14 (1994), 199-211

[65]. Z. Cai, R.D. Lazarov, T.A. Manteuffel, and S.F. McCormick, First order systems least-squares for partial differential equations: I Discretization, SIAM J. Numer. Anal., v. 31 (6) (1994), 1785-1799. MR# 95f:65133

[64]. G. Carey, R.D. Lazarov, and A. Pehlivanov, Least-squares mixed finite elements for second order elliptic problems, SIAM J. Numer. Anal., v 31 (5) (1994), 1368-1377. MR#95i:65206

[63]. R.E. Ewing, J.E. Pasciak, R.D. Lazarov, and P.S. Vassilevski, Domain decomposition type iterative techniques for parabolic problems on locally refined grids, SIAM J. Numer. Anal., v. 30, 1993, N 6, 1537-1557, MR# 95i:65094

[62]. R.E. Ewing, R.D. Lazarov, and A. Vassilev, Adaptive techniques for time-dependent problems, Comp. Meth.Appl. Mech. and Eng., v. 101, 1992, N 3, 113-126

[61]. A.I. Pehlivanov, G. Carey, R.D. Lazarov, and Y. Shen) Convergence analysis of the least-square mixed finite elements Computing, v. 51, 1993, 111-123. MR# 95b:65096

[60]. R.E. Ewing and R.D. Lazarov, Superconvergence of the mixed finite element approximations of parabolic problems using rectangular finite elements (with R.Ewing), East-West J. Numer. Mathematics, v.1, 1993, N3, 199-212. MR# 94m:65158

[59]. P.S. Vassilevski, R.D. Lazarov, and S.I. Petrova, Finite difference schemes on triangular cell-centered grids with local refinement, SIAM J. Statistical and Scientific Computation, v. 13, (1992), N6, 1287-1313

[58]. R.E. Ewing, R.D. Lazarov, and J. Wang, Superconvergence of the velocity along the Gauss lines in the mixed finite element methods, SIAM J. Numer. Anal., v.28, (1991), 4, 1015-1029

[57]. S. Chow, G. Carey, and R.D. Lazarov, Natural and postprocessed superconvergence in semi-linear problems, Numer. Methods for Partial Diff. Equations, v.7, (1991) 4, 245-259

[56]. R. Ewing, R. Lazarov, and P. Vassilevski, Finite difference schemes on grids with local refinement in time and in space for parabolic problems.II. Optimal order two-grid iterative methods. Notes on Numerical Fluid Mechanics, W.Hackbusch (Ed.) v.25 (1990), 70-93

[55]. R. Ewing, R. Lazarov, and P. Vassilevski, Finite difference schemes on grids with local refinement in time and in space for parabolic problems.I.Derivation, stability and error analysis, Computing, v.45, 1990, 193-215

[54]. R.D. Lazarov, V. Manolov, A. Yotova, and Tz. Rashev, Investigation of temperature fields of steel metallurgical blocks by the finite element method, Comptes Rend. l'Acad. Bulg. Sci., v.42 (1989), 4, 51-54

[53]. R.E. Ewing, R.D. Lazarov, and P.S. Vassilevski, Local refinement techniques for elliptic problems on cell centered grids. III. Algebraic multilevel BEPS preconditioners, Numer. Mathematik, v. 58 (1991), 5, 431-452

[52]. R.E. Ewing, R.D. Lazarov, and P.S. Vassilevski, Local refinement techniques for elliptic problems on cell centered grids. II. Two-grid iterative methods, J. Numerical Linear Algebra and Applications, v. 1 (4) (1994), 337-368

[51]. R.E. Ewing, R.D. Lazarov, and P.S. Vassilevski, Local refinement techniques for elliptic problems on cell centered grids. I. Error analysis, Math. Comp., v. 56, (1991), N 194, 437-461

[50]. A. Pehlivanov, G.F. Carey, S.S.Show, and R.D. Lazarov, Superconvergence analysis of the approximate boundary-flux calculations, Numer. Math., v. 63 (1992), 483-501

[49]. S. Chow and R.D. Lazarov, Superconvergence analysis of flux computations for nonlinear two-point boundary value problems, Preprint CMA-R09-88, Australian Nat. University (1988) and Bull.Austr.Math.Soc., v.40 (1989), 465-480, Zb#676.65096

[48]. K.N. Godev, R.D. Lazarov, V.L. Makarov, and A.A. Samarskii, Homogeneous difference schemes for one dimensional problems with generalized solutions, Math. USSR Sbornik, v.59(1) (1988), 155-179, MR#88h:65145, Zb#621.65094

[47]. A.B. Andreev and R.D. Lazarov, Superconvergence of the gradient for quadratic triangular finite elements, Numerical Methods for Partial Diff. Equations, v.4(1) (1988), 15-32, Zb#644.65082

[46]. A.B. Andreev and R.D. Lazarov, Lumped mass finite element method for parabolic and eigenvalue problems, Mathematika Balkanica, New Series, v.2(1) (1988),84-92, Zb#000.65108

[45]. R.D. Lazarov and V. Pasheva, Boundary element method for 2-D problems of ideal fluid flows with free boundaries, Adv. Water Resources, v.12 (1989), 37-45

[44]. K.N. Godev and R.D. Lazarov, Error estimates of finite difference schemes for parabolic equations with generalized solutions, Ann. de l'Universite de Sofia "Kl. Ohridski", Fac. de Math., v.79(1) (1985),403-413

[43]. R.D. Lazarov and P. Peykov, Modelling and investigation by simulation of semiconductor pressure sensors, Bulg. J. Physics, v.14(6) (1987), 530-541

[42]. R.D. Lazarov and V.L. Makarov, Difference schemes of second order accuracy for the axially symmetric Poisson equation on generalized solutions, Soviet Math. Dokl., v.25 (1982), 15-19, MR #83h:65114, Zb#488.65041

[41]. K.N. Godev and R.D. Lazarov, On the convergence of the difference scheme for the second boundary value problem for the biharmonic equation with solution from W^m , Math. Models in Phys. Chem. and Numerical Methods of Their Realization, Teubner-texte zur Math., v.61 (1985), 130-141, MR#87b:65175, Zb #542.65054

[40]. R.D. Lazarov, W. Weinelt and U. Streit, On the convergence order of difference schemes for weak solutions of the heat equation, Diff. Equations, v.20(7) (1984) (Russian), MR #86b:65105, Zb # 554. 65068

[39]. K.N. Godev and R.D. Lazarov, Error estimates of finite difference schemes in L_p-metrics for parabolic boundary value problems, Comptes Rend. l'Acad. Bulg. Sci., v.37 (1984), 565-568, Zb #567.65069, MR#86e:65137

[38]. R.D. Lazarov, V.L. Makarov, and W. Weinelt, On the convergence of difference schemes for the approximation of solutions u from W^m (m>0.5) of elliptic equations with mixed derivatives, Numer. Math., v.44 (1984), 223-232, MR #86f:65181,Zb #525.65069

[37]. I.Gavriliuk, R. Lazarov, V. Makarov. I. Pirnazarov, Estimates of the rate of convergence of difference schemes for fourth order elliptic equations, USSR J. Comput. Math. and Math. Physics, v.23(2) (1983), 64-70, MR #85g:65115, Zb#541.65064

[36]. R.D. Lazarov, V.L. Makarov, and A.A. Samarskii, Application of exact difference schemes to the construction and study of difference schemes for generalized solutions, Math. USSR Sbornik, v.45(4) (1983), 461-171, MR #84g:65137, Zb #512.65068

[35]. I.Gavriliuk, R. Lazarov, V. Makarov. I. Pirnazarov, Error estimates for difference schemes for the second boundary value problem of biharmonic equation with minimal requirements of smoothness, Dop. Acad. Sci. Ukrain. SSR, ser. A, 2 (1983), 6-9, MR #85j:65039, Zb #541.65063

[34]. R.D. Lazarov, V.L. Makarov, and W. Weinelt, On the convergence of difference schemes for elliptic equations with mixed derivatives and generalized solutions, Diff. Equations, v.19(7) (1983), 838-843, MR #85a:65153, Zb #547.65069

[33]. R.D. Lazarov and Yu.I. Mokin, On the computation of the logarithmic potential, Soviet Math. Dokl., v.28 (1983), 320-323, MR #86d:31008, Zb #567.65070

[32]. R.D. Lazarov, On the numerical solution of some axially-symmetric elastic problems by finite difference method, Diff. Equations, v.19(3) (1983), 500-507 (Russian), MR #84f:65076, Zb#534.73066

[31]. I. Dimov, Bl. Sendov, V. Manolov, R. Lazarov, T. Rashev, Mathematical modelling of crystalization of steel blocks, Trudy Inst. of Metallurgy, v.14(1) (1983), 93-102 (with I.Dimov et al., Bulgarian)

[30]. R.D. Lazarov, Convergence of difference method for parabolic equations with generalized solutions, Pliska, v.5 (1982), 51-59 (Russian), MR #84m:65105, Zb #563.65063

[29]. R.D. Lazarov, Error estimates of the finite difference schemes for parabolic problems on generalized solutions, Comptes Rend. l'Acad. Bulg. Sci., v.35(1) (1982), 7-10 (Russian), MR #84a:65081 Zb #524.65067

[28]. R.D. Lazarov, On the convergence of the finite difference schemes for Poisson equation in discrete H^1-norms, p=2, Wiss. Beitr. IH Wismar, v.7 (1982), 86-90

[27]. R.D. Lazarov and Yu.I. Mokin, On the convergence of the difference schemes for Poisson equation in L_p-metrics, Soviet Math. Dokl., v.24 (1981), 590-594, MR #83d:65272, Zb #524.65066

[25]. R.D. Lazarov and V.L. Makarov, Difference schemes of second order of accuracy for the axisymmetric Poisson equation with generalized solutions, USSR J. Comput. Math. and Math. Phys, v.21(5) (1981), 95-107, MR #84b:65100, Zb #485.65066

[25]. R.D. Lazarov, On the convergence of the difference schemes for some axisymmetric problems of mathematical physics in classes of generalized solutions, Soviet Math. Dokl., v.23 (1981), 667-670 MR#83h: 65115, Zb #524.65065

[24]. R.D. Lazarov and V.L. Makarov, Convergence of the difference methods and the methods of lines for multidimensional problems in classes of generalized solutions, Soviet Math. Dokl., v.23 (1981), 69-73, MR #83a:35004, Zb #485.65069

[23]. R.D. Lazarov, Convergence of finite difference schemes on generalized solutions of the biharmonic equation on a rectangle, Diff. Equations, v.17 (7) (1981), 836-842, MR #83h:65116, Zb #485.65068

[22]. R.D. Lazarov, On the convergence of the difference schemes for Poisson equation with generalized solutions, Diff. Equations, v.17 (7) (1981), 829-836, MR #83f:65169, Zb #485.65067

[21]. K. Gergiev and R.D. Lazarov, An error estimate for the decomposed finite element solution of the polyharmonic equation, Mathematics - Revue d'Analyse Numerique et de Theorie d'Approximation, v.23 (1981), 31-34 (K.Georgiev), MR#83g:65106, Zb #477.57015

[20]. I. Dimov, Bl. Sendov, V. Manolov, R. Lazarov, T. Rashev, Mathematical modelling of heat conduction in ingot casting of stainless steel, Metallurgy, v.36 (1981),3-5 (Russian)

[19]. R.D. Lazarov and E. Varbanova, Numerical solution of a coupled problem of elasticity, Ann. VUZ, Appl. Math., v.16(4) (1980), 179-191 (Bulgarian), MR # 83d:73080b, Zb# 497.73005

[18]. I. Dimov, Bl. Sendov, V. Manolov, R. Lazarov, Mathematical models of cristalization of block of nitrogen steel, casted in cylindrical forms, Material Sci. and Technology, v.9 (1980), 63-68 (Bulgarian)

[17]. R.D. Lazarov and E. Varbanova, Difference schemes for 1-D coupled dynamic problems of thermoelasticity, Ann. VUZ Appl. Math., v.16 (4) (1980), 167-178, (Russian), MR # 83d:73080a, Zb# 497.73004

[16]. R.D. Lazarov and G. Meladze, Factorized schemes for the dynamic problems of elastic vibrations of an unbounded strip, Trudy Tbilissi State University, v.207 (1979), 14-26 (Russian), Zb # 462.73038

[15]. K. Ganev and R.D. Lazarov, An application of the splitting method for solving some problems of mesometeorology, Bulgarian Geophysical J., v. 5 (1979), 11-21 (Russian)

[14]. R.D. Lazarov, Factorized finite difference schemes of second order accuracy for solving dynamic problems of elasticity, Comptes Rend. de l'Acad. Bulg. Sci., v.32 (1979), 1, 7-10 (Russian), Zb # 432.73079 MR# 80f:65133

[13]. R.D. Lazarov and G. Meladze, On the application of difference schemes for solving the problem of a vibrating elastic strip, Bull. Acad. Sci. Georgian SSR, v.83 (1976), 17-21 (Russian)

[12]. R.D. Lazarov, Difference schemes of second order accuracy for the axisymmetric problems of elasticity in a cylinder, Comptes Rend. de l'Acad. Bulg. Sci., v.29 (1976), 21-24 (Russian), Zb# 366.73011

[11]. R.D. Lazarov and L.Stoyanov, Difference schemes for mixed boundary value problems of elasticity on triangular grids, Comm. VMEI Gabrovo, v.8 (1976), 53-62 (Bulgarian)

[10]. P. Gospodinov, G. Saev, and R. Lazarov, Computing transient temperature fields by the finite element method, Mashinostroenie, v.1 (1976), 23-26 (Bulgarian)

[9]. R.D. Lazarov and P.Panayotov, Solving an axially-symmetric elastic problem by projection difference method, Ann. VUZ, Applied Mathematics, v.12 (2) (1976) (Bulgarian), Zb# 432.73080

[8]. R.D. Lazarov, A factored scheme for an axially-symmetric dynamic problem of elasticity, Ann. VIZ, Appl. Mathematics, v.11 (2) (1975), 103-112 (Russian), Zb# 395.73076

[7]. Chr. Butzev, A. Hachikian, and R.D. Lazarov, On calculation of axially-symmetric electric fields, Ann. Ecole Superieur de Mines et de Geologie, v.21 (1) (1975), 133-140 (Bulgarian)

[6] R.D. Lazarov and E. Varbanova Numerical solution to mixed boundary value problems of elasticity in orthotropic cylinders, Ann. VUZ, Appl. Math., v.10 (4) (1974) (Bulgarian), Zb# 343.73011

[5]. R.D. Lazarov and Yu.I. Mokin, On the stability of elliptic difference schemes, USSR J. Comput. Math. and Math. Physics, v.13 (2) (1973), 282-291 (Russian), Zb # 432.73079

[4]. R.D. Lazarov, Difference schemes for problems of elasticity in domains with curvilinear boundaries. II. Error estimate. Numerical experiments, Theoretical and Appl. Mech., v.4 (2) (1973), 133-124 (Russian)

[3]. R.D. Lazarov, Difference schemes for problems of elasticity in domains with curvilinear boundaries. I. Construction of the difference scheme. A priori estimate. Theoretical and Appl. Mech., v.2 (4) (1972), 19-30 (Russian)

[2]. R.D. Lazarov, Variational-difference schemes for axisymmetric problems of elasticity, Seminar of the Inst. Appl. Math., Georgian State Univ., 5 (1971), 77-83 (Russian).

[1]. R.D. Lazarov, Difference schemes for the second boundary value problem of elasticity for domains with curved boundaries, USSR J. Comp. Math. and Math. Physics, v.11 (4) (1971), 166-179.