1. Thomée, V., Spline Approximation for Difference Schemes for the Heat Equation, The Mathematical Foundations of the Finite Element Method, with Applications to Partial Differential Equations, Edited by A. K. Aziz, Academic Press, New York, New York, 1972.
2. Thomée, V., and Wendroff, B., Convergence Estimates for Galerkin Methods for Variable Coefficient Initial-Value Problems, SIAM Journal on Numerical Analysis, Vol. 11, pp. 1059–1068, 1974.
3. Douglas, J., Jr., and Dupont, T., Galerkin Approximations for the Two-Point Boundary-Value Problem Using Continuous Piecewise Polynomial Spaces, Numerische Mathematik, Vol. 22, pp. 99–109, 1974.
4. Dupont, T., A Unified Theory of Superconvergence for Galerkin Methods for Two-Point Boundary-Value Problems, SIAM Journal on Numerical Analysis, Vol. 13, pp. 362–369, 1976.
5. De Boor, C., and Swartz, B., Collocation at Gaussian Points, SIAM Journal on Numerical Analysis, Vol. 10, pp. 582–606, 1973.