@article{GDZPPN002323923, title = {A Characterization of the Ball by its Intrinsic Metrics.}, journal = {Mathematische Annalen}, volume = {264}, year = {1983}, pages = {271-276}, zbl = {0501.32002}, url = {http://dml.mathdoc.fr/item/GDZPPN002323923} }
Stanton, Charles M. A Characterization of the Ball by its Intrinsic Metrics.. Mathematische Annalen, Tome 264 (1983) pp. 271-276. http://gdmltest.u-ga.fr/item/GDZPPN002323923/