@article{GDZPPN002482290,
title = {Surfaces with Parallel Normalized Mean Curvature Vector.},
journal = {Monatshefte f\"ur Mathematik},
volume = {90},
year = {1980},
pages = {185-194},
zbl = {0435.53040},
url = {http://dml.mathdoc.fr/item/GDZPPN002482290}
}
Chen, Bang-Yen. Surfaces with Parallel Normalized Mean Curvature Vector.. Monatshefte für Mathematik, Tome 90 (1980) pp. 185-194. http://gdmltest.u-ga.fr/item/GDZPPN002482290/