%0 Journal Article
%A V. D. Zakharov
%T A physical characteristic of Einsteinian spaces of the second degenerate type in the Petrov classification
%J Doklady Akademii Nauk
%D 1965
%P 563-565
%V 161
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1965_161_3_a18/
%G ru
%F DAN_1965_161_3_a18