@article{01140261,
title = {The Neumann problem for the 2-D Helmholtz equation in a domain, bounded by closed and open curves.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {21},
year = {1998},
pages = {209-216},
doi = {10.1155/S0161171298000301},
zbl = {0910.35040},
language = {en},
url = {http://dml.mathdoc.fr/item/01140261}
}
Krutitskii, P.A. The Neumann problem for the 2-D Helmholtz equation in a domain, bounded by closed and open curves.. International Journal of Mathematics and Mathematical Sciences, Tome 21 (1998) pp. 209-216. doi : 10.1155/S0161171298000301. http://gdmltest.u-ga.fr/item/01140261/