@article{04048278,
title = {An inverse problem for Helmholtz's equation.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {10},
year = {1987},
pages = {825-827},
doi = {10.1155/S0161171287000929},
zbl = {0643.35110},
language = {en},
url = {http://dml.mathdoc.fr/item/04048278}
}
Ramm, A.G. An inverse problem for Helmholtz's equation.. International Journal of Mathematics and Mathematical Sciences, Tome 10 (1987) pp. 825-827. doi : 10.1155/S0161171287000929. http://gdmltest.u-ga.fr/item/04048278/