Existence results for variational-hemivariational problems with lack   ofconvexity
  We establish existence results of Hartmann-Stampacchia type for a class of variational-hemivariationalinequalities on closed and convex sets (either bounded or unbounded) in a Hilbert space. 
Vicentiu Radulescu (IMAR), Du\v{s}an Repov\v{s}
math.AP