@article{GDZPPN00208581X, title = {A general non-linear convexity theorem.}, journal = {Forum mathematicum}, volume = {9}, year = {1997}, pages = {613-640}, zbl = {0888.22005}, url = {http://dml.mathdoc.fr/item/GDZPPN00208581X} }
Neeb, Karl-Hermann. A general non-linear convexity theorem.. Forum mathematicum, Tome 9 (1997) pp. 613-640. http://gdmltest.u-ga.fr/item/GDZPPN00208581X/