1. Differential properties of the support function of the ε-subdifferential of a convex function;Auslender;C. r. hebd. Séanc. Acad. Sc. Paris,1981
2. Convex Surfaces;Busemann;Interscience Tracts in Pure and Applied Mathematics,1958
3. Generalized gradients and applications;Clarke;Trans. Am. math. Soc.,1975
4. On the inverse function theorem;Clarke;Pacific J. Math.,1976