SEN, R. N. On an Algebraic System of Riemannian Spaces. The Journal of the Indian Mathematical Society, [S. l.], v. 29, n. 4, p. 169–185, 1965. DOI: 10.18311/jims/1965/16814. Disponível em: http://informaticsjournals.com/index.php/jims/article/view/16814. Acesso em: 4 may. 2024.