[1] A. FRIEDMAN: 
Partial Differential Equations. Holt, Rinehart and Winston, Mew York, 1969. 
MR 0445088 | 
Zbl 0224.35002[2] A. V. KRYANEV: An iterative method for solving incorrectly posed problems. U.S.S.R. Computational Math. and Math. Phys. 14 (1974), 24-33.
[3] R. LATTES J. L. LIONS: 
The Method of Quasi-Reversibility: Applications to Partial Differential Equations. (translated by R. Bellman), American Elsevier, New York, 1969. 
MR 0243746[4] J. ORTEGA W. C. RHEINBOLDT: 
Iterative Solution of Nonlinear Equations in Several Variables. Academic Press, New York, 1970. 
MR 0273810[5] F. RIESZ B. Sz.-NAGY: 
Functional Analysis. (translated by L. F. Boron), Ungar, New York, 1955. 
MR 0071727