@article{01051455, title = {On the solvability of the multidimensional version of the first Darboux problem for a model second-order degenerating hyperbolic equation.}, journal = {Georgian Mathematical Journal}, volume = {4}, year = {1997}, pages = {341-354}, doi = {10.1023/A:1022942528940}, zbl = {0880.35079}, language = {en}, url = {http://dml.mathdoc.fr/item/01051455} }
Kharibegashvili, S. On the solvability of the multidimensional version of the first Darboux problem for a model second-order degenerating hyperbolic equation.. Georgian Mathematical Journal, Tome 4 (1997) pp. 341-354. doi : 10.1023/A:1022942528940. http://gdmltest.u-ga.fr/item/01051455/