%0 Journal Article
%A Zelinka, Bohdan
%T Hasse's operator and directed graphs
%J Časopis pro pěstování matematiky
%D 1967
%P 313-317
%V 092
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.21136/CPM.1967.108397/
%R 10.21136/CPM.1967.108397
%G en
%F 10_21136_CPM_1967_108397