Generalized differentials of nonsmooth functions, and necessary conditions for an extremum

On the variational principle

Ivar Ekeland · Journal of Mathematical Analysis and Applications · 1974 · 2.3K citations · Full text

Natural Sciences, Mathematics, Physics +10

Generalized gradients and applications

Frank H. Clarke · Transactions of the American Mathematical Society · 1975 · 1.2K citations

Natural Sciences, Mathematics, Derivatives +10

A New Approach to Lagrange Multipliers

Frank H. Clarke · Mathematics of Operations Research · 1976 · 502 citations

Natural Sciences, Mathematics, Algorithms +11

Generalized Directional Derivatives and Subgradients of Nonconvex Functions

R. T. Rockafellar · Canadian Journal of Mathematics · 1980 · 412 citations · Full text

Natural Sciences, Mathematics, Derivatives +10

Tangent Cones, Generalized Gradients and Mathematical Programming in Banach Spaces

Jean-Baptiste Hiriart-Urruty · Mathematics of Operations Research · 1979 · 399 citations

Natural Sciences, Mathematics, Cost-minimization Analysis +16