1. [1] Asplund, S. O.: Finite boundary value problems solved by Green's matrix, Math. Scand., 7 (1959), 49- 56.
2. [2] Bublik, B. N. and G. N. Polozhii: Eigenvalues of the basic biharmonic problem for a rectangle, Dopovidi Akad. Nauk Ukrain, RSR, (1967), 3-6.
3. [3] Buledza, A. V.: On an approximate method of solving boundary problems for biharmonic equations, Dokl. Akad. Nauk SSSR, 170 (1966), 495-496.
4. [4] Buledza, A. V.: On difference methods for solution of boundary-value problems for differential equations of elliptic type, Differential'nye Uravnenija, 1 (1965), 687-691.
5. [5] Conte, S. D. and T. T. Dames: An alternating direction method for solving the biharmonic equation, Math. Tables Aids Comput., 12 (1958), 198-205.