@article{CRMATH_2004__339_11_803_0,
     author = {Berm\'udez, Alfredo and Hervella-Nieto, L. and Prieto, A. and Rodr{\'\i}guez, R.},
     title = {An exact bounded {PML} for the {Helmholtz} equation},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {803--808},
     publisher = {Elsevier},
     volume = {339},
     number = {11},
     year = {2004},
     doi = {10.1016/j.crma.2004.10.006},
     language = {en},
     url = {http://archive.numdam.org/articles/10.1016/j.crma.2004.10.006/}
}