1. and , Survey Lectures on the Mathematical Fundations of the Finite Element Method, in The Mathematical Foundations of the Finite Element Method with Applications to Partial Differential Equations, Academic, New York and London, 1972.
2. and , An Introduction to the Mathematical Theory of Finite Elements, Wiley, New York, 1976.
3. Boundary Methods: An Algebraic Theory, Pitman Advanced Publishing Program, Boston, London. 1984.
4. Unified formulation of numerical methods. I. Green's formulas for operators in discontinuous fields
5. Unified approach to numerical methods, part II: Finite elements, boundary methods, and their coupling