@article{00770113, title = {On a spatial problem of Darboux type for a second-order hyperbolic equation.}, journal = {Georgian Mathematical Journal}, volume = {2}, year = {1995}, pages = {299-311}, doi = {10.1007/BF02261703}, zbl = {0829.35069}, language = {en}, url = {http://dml.mathdoc.fr/item/00770113} }
Kharibegashvili, S. On a spatial problem of Darboux type for a second-order hyperbolic equation.. Georgian Mathematical Journal, Tome 2 (1995) pp. 299-311. doi : 10.1007/BF02261703. http://gdmltest.u-ga.fr/item/00770113/