TY  - JOUR
AU  - Rockafellar, R. T.
TI  - Generalized Directional Derivatives and Subgradients of Nonconvex Functions
JO  - Canadian journal of mathematics
PY  - 1980
SP  - 257
EP  - 280
VL  - 32
IS  - 2
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1980-020-7/
DO  - 10.4153/CJM-1980-020-7
ID  - 10_4153_CJM_1980_020_7
ER  -