%0 Journal Article %A Hall, Robert E. %T Commutative cancellative semigroups with two generators %J Czechoslovak Mathematical Journal %D 1971 %P 449-452 %V 21 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1971.101046/ %R 10.21136/CMJ.1971.101046 %G en %F 10_21136_CMJ_1971_101046