@article{02100237, title = {Ball versus distance convexity of metric spaces.}, journal = {Beitr\"age zur Algebra und Geometrie}, volume = {45}, year = {2004}, pages = {481-500}, zbl = {1070.53046}, language = {en}, url = {http://dml.mathdoc.fr/item/02100237} }
Foertsch, Thomas. Ball versus distance convexity of metric spaces.. Beiträge zur Algebra und Geometrie, Tome 45 (2004) pp. 481-500. http://gdmltest.u-ga.fr/item/02100237/