@article{DE_1978_14_5_a6,
     author = {Bularas Driss and M. N. Popa},
     title = {Concomitants of a system with quadratic nonlinearities},
     journal = {Differencialʹnye uravneni\^a},
     pages = {835--842},
     publisher = {mathdoc},
     volume = {14},
     number = {5},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1978_14_5_a6/}
}