1. Lectures on Elliptic Boundary Value Problems;Agmon,1965
2. “Behavior of the Error of the Approximate Solutions of Boundary Value Problems for Linear Elliptic Operators by Galerkin's and Finite Difference Methods,”;Aubin;Annali della Scuola Normale di Pisa,1967
3. “Interpolation et approximation optimales et ‘Spline Functions’,”;Aubin;J. Math. Anal, Appl.,1968
4. Babuška, I., “Numerical Solution of Boundary Value Problems by the Perturbed Variational Principle,” Univ. of Maryland Tech. Note BN-624, Oct. 1969.
5. Babuška, I., “Approximation by Hill Functions,” Univ. of Maryland Tech. Note BN-648.