Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1969_5_1_a15, author = {G. D. Karatoprakliev}, title = {A certain class of equations of mixed type}, journal = {Differencialʹnye uravneni\^a}, pages = {199--205}, publisher = {mathdoc}, volume = {5}, number = {1}, year = {1969}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1969_5_1_a15/} }
G. D. Karatoprakliev. A certain class of equations of mixed type. Differencialʹnye uravneniâ, Tome 5 (1969) no. 1, pp. 199-205. http://geodesic.mathdoc.fr/item/DE_1969_5_1_a15/