Nonlinear Operators and the Calculus of Variations : Summer School Held in Bruxelles 8–19 September 1975 Nonlinear operators in ordered Banach spaces and some applications to nonlinear boundary value problems Quelques proprietes des operateurs monotones et des semi groupes non lineaires Implicit variational problems and quasi variational inequalities Integral functionals normal integrands and measurable selections Applications de lanalyse convexe au calcul des variations.