%0 Journal Article
%A Umar, A.
%T Combinatorial results for semigroups of orientation-preserving partial transformations.
%J Journal of integer sequences
%D 2011
%V 14
%N 7
%I mathdoc
%U http://geodesic.mathdoc.fr/item/JIS_2011__14_7_a7/
%G en
%F JIS_2011__14_7_a7