%0 Journal Article
%A Rockafellar, R. T.
%T Generalized Directional Derivatives and Subgradients of Nonconvex Functions
%J Canadian journal of mathematics
%D 1980
%P 257-280
%V 32
%N 2
%U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1980-020-7/
%R 10.4153/CJM-1980-020-7
%F 10_4153_CJM_1980_020_7