@article {1989, title = {Upper semicontinuous differential inclusions without convexity}, journal = {Proc. Amer. Math. Soc. 106 (1989), no. 3, 771-775}, number = {SISSA;74/88/M}, year = {1989}, publisher = {SISSA Library}, url = {http://hdl.handle.net/1963/670}, author = {Alberto Bressan and Arrigo Cellina and Giovanni Colombo} }