%0 Journal Article
%A Biryukov, Petr A.
%T Cardinalities and ranks of $\pi$-bases in topological spaces
%J Commentationes Mathematicae Universitatis Carolinae
%D 1980
%P 769-776
%V 21
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMUC_1980__21_4_a12/
%G en
%F CMUC_1980__21_4_a12