%0 Journal Article %A V. G. Romanovsky %A M. Robnik %T Computation of the Center Isochronism Conditions for Polynomial Systems %J Differencialʹnye uravneniâ %D 2002 %P 195-200 %V 38 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_2002_38_2_a5/ %G ru %F DE_2002_38_2_a5