Bilevel programs with extremal value function: global optimality. - Abdelmalek Aboussoror; Hicham Babahadda; Abdelatif Mansouri (Int. J. Math. Math. Sci., 2005)

Necessary Optimality Conditions for Bilevel Optimization Problems Using Convexificators. - Hicham Babahadda; Nazih Abderrazzak Gadhi (J. Glob. Optim., 2006)