@article{MZ_1959__72_183594, author = {Charles Loewner}, title = {A theorem on the partial order derived from a certain transformation semigroup.}, journal = {Mathematische Zeitschrift}, pages = {53--60}, publisher = {mathdoc}, volume = {72}, year = {1959}, zbl = {0091.26101}, url = {http://geodesic.mathdoc.fr/item/MZ_1959__72_183594/} }