Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1972_8_5_a11, author = {P. P. Zabreiko and Yu. I. Fetisov}, title = {The method of a small parameter for hyperbolic equations}, journal = {Differencialʹnye uravneni\^a}, pages = {823--834}, publisher = {mathdoc}, volume = {8}, number = {5}, year = {1972}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1972_8_5_a11/} }
P. P. Zabreiko; Yu. I. Fetisov. The method of a small parameter for hyperbolic equations. Differencialʹnye uravneniâ, Tome 8 (1972) no. 5, pp. 823-834. http://geodesic.mathdoc.fr/item/DE_1972_8_5_a11/