%0 Journal Article
%A P. S. Aleksandrov
%A A. D. Myshkis
%A O. A. Oleinik
%T Ivan Georgievich Petrovskii (on the occasion of his sixtieth birthday)
%J Trudy Matematicheskogo Instituta imeni V.A. Steklova
%D 1961
%P 131-149
%V 16
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/RM_1961_16_3_a2/
%G en
%F RM_1961_16_3_a2