%0 Journal Article
%A Chajda, Ivan
%T Relational classes and their characterizations
%J Archivum mathematicum
%D 1980
%P 199-203
%V 16
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/ARM_1980__16_4_a2/
%G en
%F ARM_1980__16_4_a2