Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1991_27_4_a16, author = {N. S. Berezkina and I. P. Martynov}, title = {A system of partial differential equations}, journal = {Differencialʹnye uravneni\^a}, pages = {695--697}, publisher = {mathdoc}, volume = {27}, number = {4}, year = {1991}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1991_27_4_a16/} }
N. S. Berezkina; I. P. Martynov. A system of partial differential equations. Differencialʹnye uravneniâ, Tome 27 (1991) no. 4, pp. 695-697. http://geodesic.mathdoc.fr/item/DE_1991_27_4_a16/