%0 Journal Article
%A I. D. Stupina
%T Certain properties of $R$- and $R^c$-operations
%J Doklady Akademii Nauk
%D 1969
%P 1010-1013
%V 188
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1969_188_5_a12/
%G ru
%F DAN_1969_188_5_a12