%0 Journal Article %A Andrzej Karafiat %T The problem of the number of switches in parabolic equations with control %J Annales Polonici Mathematici %D 1977 %P 289-316 %V 34 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/ap-34-3-289-316/ %R 10.4064/ap-34-3-289-316 %G en %F 10_4064_ap_34_3_289_316