@article{CM_1951__9__161_0,
     author = {Huber, Heinz},
     title = {\"Uber analytische Abbildungen von Ringgebieten in Ringgebiete},
     journal = {Compositio Mathematica},
     publisher = {Kraus Reprint},
     volume = {9},
     year = {1951},
     pages = {161-168},
     zbl = {0043.30201},
     mrnumber = {43904},
     language = {de},
     url = {http://www.numdam.org/item/CM_1951__9__161_0}
}

Huber, Heinz. Über analytische Abbildungen von Ringgebieten in Ringgebiete. Compositio Mathematica, Volume 9 (1951) pp. 161-168. http://www.numdam.org/item/CM_1951__9__161_0/