1. Convex analysis;Rockefeller,1970
2. Necessary conditions for an extremum;Pshenichnyi,1969
3. Theory of external problems;Ioffe,1974
4. A class of almost-differentiable functions and a method of minimizing such functions;Shor;Kibernetika,1972
5. Generalized gradients and applications;Clarke;Trans. Amer. Math. Soc.,1975