@Article{TRB06,
  author = 	 {G. Thoreson and J. C. Ragusa and W. Bangerth},
  title = 	 {Some advances on inverse particle transport problems
                  with applications to homeland security},
  journal = 	 {Trans. Am. Nucl. Soc.},
  year = 	 2006,
  volume =	 95,
  pages =	 {534--537}
}