Preface.- Variational Formulations and Finite Element Methods.- Function Spaces and Finite Element Approximations.- Algebraic Aspects of Saddle Point Problems.- Saddle Point Problems in Hilbert spaces.- Approximation of Saddle Point Problems.- Complements: Stabilisation Methods, Eigenvalue Problems.- Mixed Methods for Elliptic Problems.- Incompressible Materials and Flow Problems.- Complements on Elasticity Problems.- Complements on Plate Problems.-...