Okun, L. B. (July 1998), "Note on the meaning and terminology of Special Relativity", European Journal of Physics, 19 (4): 403–406, doi:10.1088/0143-0807/19/4/015, S2CID250885802
Okun, L. B. (July 1998), "Note on the meaning and terminology of Special Relativity", European Journal of Physics, 19 (4): 403–406, doi:10.1088/0143-0807/19/4/015, S2CID250885802