Canfes, E. Ö., and A. Özdeğer. 2013. “A Characterization of Totally Umbilical Hypersurfaces of a Space Form by Geodesic Mapping”.
Ukrains’kyi Matematychnyi Zhurnal
65 (4): 583-87.
https://umj.imath.kiev.ua/index.php/umj/article/view/2441
.