%0 Journal Article %A Grasselli, Osvaldo Maria %A Longhi, Sauro %A Tornambè, Antonio %T On obtaining the time-invariant associated system of a periodic system through system equivalence %J Kybernetika %D 1995 %P 649-655 %V 31 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/KYB_1995__31_6_a11/ %G en %F KYB_1995__31_6_a11