@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/}
}