1. A. Einstein:Jahrb. Radioakt. Elektr.,4, 441 (1907);Ann. der Phys.,35, 898 (1911);S. B. Preuss. Akad. Wiss., 831 (1915);Ann. der Phys.,49, 760 (1916). The prediction of the effect Δt/t=−ΔU/c 2 was made byEinstein, prior to the development of the general theory, on the basis of the equivalence principle.
2. For a review of the experimental evidence since the formulation of the theory and for detailed references:Evidence for Gravitational Theories, Rendiconti S.I.F., Course XX (New York, N. Y., 1961);V. L. Ginzburg: inRecent Developments in General Relativity (New York, N.Y., 1962), p. 57;L. I. Schiff: inJourneys in Science (New Mexico, N. Mex., 1967), p. 148;J. D. Anderson:Proceedings of the Conference on Experimental Tests of Gravitation Theories (Pasadena, Cal., 1970);The Theoretical Tools of Experimental Gravitation, Rendiconti S.I.F., Course LVI (New York, N. Y., 1972).
3. R. V. Pound:Usp. Fiz. Nauk,72, 673 (1960);R. V. Pound andG. A. Rebka jr.:Phys. Rev. Lett. 4, 337 (1960);R. V. Pound andJ. L. Snider:Phys. Rev. Lett.,13, 539 (1964);Phys. Rev.,140, 788 (1965).
4. C. Egidi andS. Leschiutta Riv. Nuovo Cimento,1, 496 (1971);G. Becker:Proceedings of the II Cagliari International Meeting on Time Determination, Dissemination and Synchronisation, IAU Symposium (Cagliari, 1974), p. 63.
5. Their detailed calculations are given byN. Ashby: NBS Technical Note, No. 659 (April 1975).