%0 Journal Article
%A R. I. Khrapko
%T Defining the space type on Petrov's classification
%J Doklady Akademii Nauk
%D 1967
%P 56-57
%V 176
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1967_176_1_a13/
%G ru
%F DAN_1967_176_1_a13