@article{DE_1971_7_9_a1,
     author = {V. A. Bogachev},
     title = {Investigation of a singular point on the plane in the case of two zero roots},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1560--1567},
     publisher = {mathdoc},
     volume = {7},
     number = {9},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1971_7_9_a1/}
}