@article{1102948644, author = {Beer, Gerald}, title = {The index of convexity and the visibility function.}, journal = {Pacific J. Math.}, volume = {49}, number = {2}, year = {1973}, pages = { 59-67}, language = {en}, url = {http://dml.mathdoc.fr/item/1102948644} }
Beer, Gerald. The index of convexity and the visibility function.. Pacific J. Math., Tome 49 (1973) no. 2, pp. 59-67. http://gdmltest.u-ga.fr/item/1102948644/