Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{CMH_1939__12_138749, author = {Arnold Emch}, title = {Zwei {Abbildungs-Probleme.}}, journal = {Commentarii mathematici Helvetici}, pages = {246--253}, publisher = {mathdoc}, volume = {12}, year = {1939}, url = {http://geodesic.mathdoc.fr/item/CMH_1939__12_138749/} }
Arnold Emch. Zwei Abbildungs-Probleme.. Commentarii mathematici Helvetici, Tome 12 (1939), pp. 246-253. http://geodesic.mathdoc.fr/item/CMH_1939__12_138749/