@article{MS2_1977__41_166543, author = {Matti Vuorinen}, title = {On the {Iversen-Tsuji} theorem quasiregular mappings.}, journal = {Mathematica Scandinavica}, pages = {90--98}, year = {1977}, volume = {41}, zbl = {0375.30007}, url = {http://geodesic.mathdoc.fr/item/MS2_1977__41_166543/} }