Chapter 2 on Relativity
1 GRS Measurement By A. Cacciani Frascati, March 21th 2006.
ON TIME An Introduction into the theory behind Albert Einsteins Special Relativity.
Relativity and the Universe Chapter 30 Page 724.
Hirophysics.com PATRICK ABLES. Hirophysics.com PART 1 TIME DILATION: GPS, Relativity, and other applications.