@article{DE_1981_17_4_a18,
     author = {N. D. Vasilevich and V. I. Gromak},
     title = {Integrability of complex {Pfaff} equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {735--737},
     publisher = {mathdoc},
     volume = {17},
     number = {4},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_4_a18/}
}