@article{DE_1988_24_6_a29,
     author = {S. S. Mamonov},
     title = {Determination of the number of limit cycles of the second kind of systems of differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1076--1078},
     publisher = {mathdoc},
     volume = {24},
     number = {6},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1988_24_6_a29/}
}