%0 Journal Article %A I. I. Martynov %T Sufficient conditions for the regularity and reducibility of systems close to periodic ones %J Differencialʹnye uravneniâ %D 1968 %P 370-374 %V 4 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1968_4_2_a19/ %G ru %F DE_1968_4_2_a19