@article{1183536278, author = {Clarke, Frank H.}, title = {Maximum principles without differentiability}, journal = {Bull. Amer. Math. Soc.}, volume = {81}, number = {4}, year = {1975}, pages = { 219-222}, language = {en}, url = {http://dml.mathdoc.fr/item/1183536278} }
Clarke, Frank H. Maximum principles without differentiability. Bull. Amer. Math. Soc., Tome 81 (1975) no. 4, pp. 219-222. http://gdmltest.u-ga.fr/item/1183536278/