@article{GDZPPN002054949, title = {Dreikreisesatz und Zentrumproblem.}, journal = {Commentarii mathematici Helvetici}, volume = {21}, year = {1948}, pages = {185-188}, language = {de}, url = {http://dml.mathdoc.fr/item/GDZPPN002054949} }
Cremer, Hubert. Dreikreisesatz und Zentrumproblem.. Commentarii mathematici Helvetici, Tome 21 (1948) pp. 185-188. http://gdmltest.u-ga.fr/item/GDZPPN002054949/