Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1972_8_2_a15, author = {V. S. Ryzhii}, title = {The uniqueness of a solution of the {Cauchy} problem for second order equations}, journal = {Differencialʹnye uravneni\^a}, pages = {349--361}, publisher = {mathdoc}, volume = {8}, number = {2}, year = {1972}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1972_8_2_a15/} }
V. S. Ryzhii. The uniqueness of a solution of the Cauchy problem for second order equations. Differencialʹnye uravneniâ, Tome 8 (1972) no. 2, pp. 349-361. http://geodesic.mathdoc.fr/item/DE_1972_8_2_a15/