Relativity, Addison-Wesley, 2003. A graduate-level general relativity textbook. A. S. Eddington, Space, Time and Gravitation, Cambridge University Press, reprint of 1920 ed. A. Gefter, "Putting Einstein to the Test", Sky and Telescope July 2005, p. 38. A popular discussion of tests of general relativity. H. Ohanian and R. Ruffini, Gravitation and Spacetime, 2nd Edition Norton, New York, 1994, . A general relativity textbook. C. M. Will, Theory and Experiment in Gravitational Physics, Cambridge University Press, Cambridge (1993). A standard technical reference. C. M. Will, Was Einstein Right?: Putting General Relativity to the Test, Basic Books (1993). This is a popular account of tests of general relativity. Living Reviews papers N. Ashby, "Relativity in the Global Positioning System", Living Reviews in Relativity (2003). C. M. Will, The Confrontation between General Relativity and Experiment, Living Reviews in Relativity (2014). An online, technical review, covering much of the material in Theory and experiment in gravitational physics. It is less comprehensive but more up to date. (ArXiv version here: arxiv.org/abs/1403.7377 ) External links the USENET Relativity FAQ experiments page Mathpages article on Mercury's perihelion shift (for amount of observed and GR shifts). Mercury (planet)