@article{1028998668, author = {Roxin, Emilio}, title = {The existence of optimal controls.}, journal = {Michigan Math. J.}, volume = {9}, number = {1}, year = {1962}, pages = { 109-119}, language = {en}, url = {http://dml.mathdoc.fr/item/1028998668} }
Roxin, Emilio. The existence of optimal controls.. Michigan Math. J., Tome 9 (1962) no. 1, pp. 109-119. http://gdmltest.u-ga.fr/item/1028998668/