@article{ETNA_2012__39__a18,
     author = {Kleefeld, Andreas and Lin, Tzu-Chu},
     title = {Boundary element collocation method for solving the exterior {Neumann} problem for {Helmholtz's} equation in three dimensions},
     journal = {Electronic transactions on numerical analysis},
     pages = {113--143},
     publisher = {mathdoc},
     volume = {39},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_2012__39__a18/}
}