@article{GDZPPN002064790,
title = {On the Gauss map of complete surfaces of constant mean curvature in R3 and R4.},
journal = {Commentarii mathematici Helvetici},
volume = {57},
year = {1982},
pages = {519-531},
zbl = {0512.53008},
url = {http://dml.mathdoc.fr/item/GDZPPN002064790}
}
Osserman, R.; Schoen, R.; Hoffman, D.A. On the Gauss map of complete surfaces of constant mean curvature in R3 and R4.. Commentarii mathematici Helvetici, Tome 57 (1982) pp. 519-531. http://gdmltest.u-ga.fr/item/GDZPPN002064790/