@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},
     year = {1959},
     volume = {72},
     zbl = {0091.26101},
     url = {http://geodesic.mathdoc.fr/item/MZ_1959__72_183594/}
}