%0 Journal Article %A A. I. Mal'tsev %A B. I. Plotkin %T Petr Grigor'evich Kontorovich (on his sixtieth birthday) %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1965 %P 107-110 %V 20 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/RM_1965_20_4_a2/ %G en %F RM_1965_20_4_a2