@article{MM2_1987__59_155252,
     author = {J.-H. Eschenburg},
     title = {Comparison theorems and hypersurfaces.},
     journal = {Manuscripta mathematica},
     pages = {295--324},
     publisher = {mathdoc},
     volume = {59},
     year = {1987},
     zbl = {0642.53044},
     url = {http://geodesic.mathdoc.fr/item/MM2_1987__59_155252/}
}