@article{TIMM_2000_6_1_a5,
     author = {F. H. Clarke and Yu. S. Ledyaev and R. J. Stern},
     title = {Proximal analysis and feedback construction},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {91--109},
     publisher = {mathdoc},
     volume = {6},
     number = {1},
     year = {2000},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2000_6_1_a5/}
}