@article{DE_1973_9_6_a22,
     author = {V. P. Shapovalov},
     title = {Integration of certain classes of systems of two first order ordinary differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1154--1155},
     publisher = {mathdoc},
     volume = {9},
     number = {6},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_6_a22/}
}