%0 Journal Article
%A Lowenthal, Franklin
%T On Subsemigroups of the Projective Group on the Line
%J Canadian journal of mathematics
%D 1968
%P 1001-1011
%V 20
%N 1
%U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1968-097-7/
%R 10.4153/CJM-1968-097-7
%F 10_4153_CJM_1968_097_7