1. Calculus of Observations. Blackie & Son;WIHTTAKER AND ROBINSON;London,1944
2. Milne. Numerical Solution of Differential Equations. Wiley New York 10 225. Milne. Numerical Solution of Differential Equations. Wiley New York 10 225.
3. On two-line iterative meLhods for the Laplace and Biharmonic differenee equations;PARKAR S. V;Num. Math.