@article{CMH_1962__37_139253,
     author = {Lipman Bers},
     title = {The equivalence of two definitions of quasiconformal mappings.},
     journal = {Commentarii mathematici Helvetici},
     pages = {148--154},
     year = {1962},
     volume = {37},
     zbl = {0108.07702},
     url = {http://geodesic.mathdoc.fr/item/CMH_1962__37_139253/}
}