%0 Journal Article %A G. E. Popov %T A class of integrable systems with a small parameter %J Differencialʹnye uravneniâ %D 1977 %P 1214-1217 %V 13 %N 7 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1977_13_7_a6/ %G ru %F DE_1977_13_7_a6