Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{CMH_1968__43_139359, author = {H. Renggli}, title = {Doppelverh\"altnisse und quasikonforme {Abbildungen.}}, journal = {Commentarii mathematici Helvetici}, pages = {161--175}, publisher = {mathdoc}, volume = {43}, year = {1968}, zbl = {0159.10902}, url = {http://geodesic.mathdoc.fr/item/CMH_1968__43_139359/} }
H. Renggli. Doppelverhältnisse und quasikonforme Abbildungen.. Commentarii mathematici Helvetici, Tome 43 (1968), pp. 161-175. http://geodesic.mathdoc.fr/item/CMH_1968__43_139359/