1. and , An Analysis of the Finite Element Method, Prentice-Hall, N.J., 1973.
2. The Finite Element Method, 3rd edn, McGraw-Hill, London, 1977.
3. ‘Some recent advances in the mathematics of finite elements’, in The Mathematics of Finite Elements and Applications (Ed.), Academic Press, 1973, pp. 59-79.
4. ‘A method of bivariate interpolation and smooth surface fitting for values given at irregularly distributed points’, U.S. Govt Printing Office, Washington, D.C. (1975).
5. and , The Finite Element Method in Partial Differential Equations, Wiley, 1977, Sec. 4.1.