%0 Journal Article
%A B. A. Efimov
%A G. I. Chertanov
%T On some operations on classes of topological spaces
%J Doklady Akademii Nauk
%D 1974
%P 25-27
%V 216
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1974_216_1_a4/
%G ru
%F DAN_1974_216_1_a4