@article{GDZPPN002228297, title = {Comparison theorems and hypersurfaces.}, journal = {Manuscripta mathematica}, volume = {58}, year = {1987}, pages = {295-324}, zbl = {0642.53044}, url = {http://dml.mathdoc.fr/item/GDZPPN002228297} }
Eschenburg, J.-H. Comparison theorems and hypersurfaces.. Manuscripta mathematica, Tome 58 (1987) pp. 295-324. http://gdmltest.u-ga.fr/item/GDZPPN002228297/