%0 Journal Article
%A Nieminen, Juhani
%T Operations on graphs determining congruences on graphs
%J Archivum mathematicum
%D 1978
%P 215-218
%V 14
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/ARM_1978__14_4_a6/
%G en
%F ARM_1978__14_4_a6