@article{DE_1972_8_3_a23,
     author = {A. M. Tezin},
     title = {Nontopological mapping of the phase plane in the qualitative theory of first order differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {556--558},
     publisher = {mathdoc},
     volume = {8},
     number = {3},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1972_8_3_a23/}
}