@article{AIHPC_2008__25_4_773_0,
     author = {Cannarsa, P. and Rifford, L.},
     title = {Semiconcavity results for optimal control problems admitting no singular minimizing controls},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {773--802},
     publisher = {Elsevier},
     volume = {25},
     number = {4},
     year = {2008},
     doi = {10.1016/j.anihpc.2007.07.005},
     mrnumber = {2436793},
     zbl = {1145.49022},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.anihpc.2007.07.005/}
}