%0 Journal Article
%A V. V. Ryzhkov
%T Characteristic directions of a~point mapping of $P_m$ into~$P_n$
%J Itogi Nauki i Tekhniki. Seriya Problemy Geometrii. Trudy Geometricheskogo Seminara
%D 1971
%P 235-242
%V 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/INTG_1971_3_a10/
%G ru
%F INTG_1971_3_a10