1. http://en.wikipedia.org/wiki/Galilean_transformation
2. V.S. Soni Mechanics and Relativity (Patparganj Dehi: PHI, Learning Private Limited) (2009).
3. J.D. Cresser SpecialRelativityNotes.pdf.2.
4. P. Tourrenc Relativity and Gravitation (United Kingdom" University of Cambridge) (1997).
5. A.A.Michelson and E. W. Morley Am. J. Science31(1886)377.