%0 Journal Article
%A M. Malec
%A Z. Skupień
%T On the maximal planar graphs and the four colour problem
%J Commentationes Mathematicae
%D 1969
%P  205-209
%V 12
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.14708/cm.v12i2.5139/
%R 10.14708/cm.v12i2.5139
%G pl
%F 10_14708_cm_v12i2_5139