@article{DE_1981_17_9_a10,
     author = {V. P. Pisarenok},
     title = {Singularities of a system of differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1630--1634},
     publisher = {mathdoc},
     volume = {17},
     number = {9},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_9_a10/}
}