tenseur de Ricci
1991 / The rejection of the ricci tensor in Einstein's first tensorial theory of gravitation / Giulio Maltese / Archive for history of exact sciences 41 (1991) p. 363 [doi]
1995 / The Ricci tensor of a diagonal metric / J. B. Boyling / American Journal of Physics 63 (1995) p. 168 [doi]