1. Walker, S.—Application of Theory of Probability to Design of Concrete for Strength Specifications, paper presented at 14th Annual Meeting of the National Ready-Mixed Concrete Association, New York, January 27, 1944, N.R.M.C.A. Publication No. 57, Washington, D.C., p. 7.
2. A.C.I. Committee 214.—Recommended Practice for Evaluation of Compression Test Results of Field Concrete (A.C.I. 214-65), in A.C.I. Book of Standards, Part 1, Detroit, 1967.
3. British Standard Code of Practice C.P. 114: 1957.—The Structural Use of Reinforced Concrete. British Standard Institution, London, 1957.
4. Mudrock L. J..—The Control of Concrete Quality. Proceedings of the Institution of Civil Engineers, Part I, Vol. 2, No. 4, July 1953, pp. 426–453.
5. Research Report;H. C. Erntroy,1960