1. L. FOX: “An Introduction to Numerical Linear Algebra”, Clarendon Press, Oxford, 1964.
2. G. U. YULE and M. G. KENDALL: “An Introduction to the Theory of Statistics”, 14th edition., Griffin and Co. Ltd., London, 1958.
3. G. BOMFORD: “Geodesy”, 2nd edition, Clarendon Press, Oxford, 1962.