@article{00753680, title = {On the spectrum of the negative Laplacian for general doubly-connected bounded domains.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {18}, year = {1995}, pages = {245-254}, doi = {10.1155/S0161171295000305}, zbl = {0829.35090}, language = {en}, url = {http://dml.mathdoc.fr/item/00753680} }
Zayed, E.M.E.; Younis, A.I. On the spectrum of the negative Laplacian for general doubly-connected bounded domains.. International Journal of Mathematics and Mathematical Sciences, Tome 18 (1995) pp. 245-254. doi : 10.1155/S0161171295000305. http://gdmltest.u-ga.fr/item/00753680/