%0 Journal Article
%A Havel, Václav
%T Universality property of free groupoid extensions of halfgroupoids and its geometrical meaning
%J Czechoslovak Mathematical Journal
%D 1975
%P 562-567
%V 25
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1975.101352/
%R 10.21136/CMJ.1975.101352
%G en
%F 10_21136_CMJ_1975_101352