@article{10_1017_S0017089500010119,
     author = {Koh, Sung-Eun},
     title = {Sphere theorem by means of the ratio of meancurvature functions},
     journal = {Glasgow mathematical journal},
     pages = {91--95},
     year = {2000},
     volume = {42},
     number = {1},
     doi = {10.1017/S0017089500010119},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500010119/}
}