1. Introductory Numerical Analysis of Elliptic Boundary Value Problems;Greenspan,1965
2. On nonlinear differential equations, the maximum operation, and monotone convergence;Kalaba;J. Math. Mech.,1959
3. Mildly nonlinear elliptic partial differential equations and their numerical solution—I;Parter;Num. Math.,1965
4. Methodus Inveniendi Lineas Curvas Maximi Minimive Proprietate Gaudentes;Euler,1744
5. Refined Iterative Methods for Computation of the Solution and the Eigenvalues of Self-Adjoint Boundary Value Problems;Engeli,1959