@article{05169447, title = {Two-dimensional Helmholtz spaces.}, journal = {Sibirskij Matematicheskij Zhurnal}, volume = {46}, year = {2005}, pages = {1341-1359}, zbl = {1117.51019}, language = {en}, url = {http://dml.mathdoc.fr/item/05169447} }
Kyrov, V.A. Two-dimensional Helmholtz spaces.. Sibirskij Matematicheskij Zhurnal, Tome 46 (2005) pp. 1341-1359. http://gdmltest.u-ga.fr/item/05169447/