%0 Journal Article %A Butler, Kim Ki-Hang %A Schwarz, Štefan %T The semigroup of circulant Boolean matrices %J Czechoslovak Mathematical Journal %D 1976 %P 632-635 %V 26 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1976.101434/ %R 10.21136/CMJ.1976.101434 %G en %F 10_21136_CMJ_1976_101434