Evans, E.W (2003). "A Generally covariant field equation for gravitation and electromagnetism". Foundations of Physics Letters. 16 (4): 369–377. doi:10.1023/A:1025365826316. S2CID122087923.
Evans, E.W (2003). "A Generally covariant field equation for gravitation and electromagnetism". Foundations of Physics Letters. 16 (4): 369–377. doi:10.1023/A:1025365826316. S2CID122087923.