NAMBOORIPAD, K. S. S.; SITARAMAN, Y. A Note on Weakly Inverse Semigroups. The Journal of the Indian Mathematical Society, [S. l.], v. 40, n. 1-4, p. 145–151, 1976. Disponível em: http://informaticsjournals.com/index.php/jims/article/view/16619. Acesso em: 3 may. 2024.