@article{CMH_1982__57_139921,
     author = {Steven R. Bell},
     title = {Proper holomorphic mappings between circular domains.},
     journal = {Commentarii mathematici Helvetici},
     pages = {532--538},
     publisher = {mathdoc},
     volume = {57},
     year = {1982},
     zbl = {0511.32013},
     url = {http://geodesic.mathdoc.fr/item/CMH_1982__57_139921/}
}