@article{DE_1973_9_4_a29,
     author = {P. T. Cherevichny},
     title = {Three theorems on the {Poincar\'e} index for the equation $y'=P_4(x,y)/Q_4(x,y)$},
     journal = {Differencialʹnye uravneni\^a},
     pages = {778--779},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_4_a29/}
}