%0 Journal Article %A N. P. Erugin %T The analytic structure and fundamental properties of solutions of equations with algebroidal right-hand sides in case of focus and generalizations %J Differencialʹnye uravneniâ %D 1965 %P 303-312 %V 1 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1965_1_3_a2/ %G ru %F DE_1965_1_3_a2