The paper deals with the iterative solution of linear algebraic systems resulting from the difference solution of an elliptic partial differencital equation of a special form. In the paper two methods suitable for the case of continuous or discontinuous coefficients respectively are studied.
 R. S. Varga: Matrix Iterative Analysis
. Prentice Hall, Englewood Cliffs, New Jersey, 1962. MR 0158502
 A. S. Householder: The Theory of Matrices in Numerical Analysis
. Blaisdell Publishing Company, New York-Toronto- London, 1964. MR 0175290
| Zbl 0161.12101