RATHER, N. A.; IBRAHIM, M. Generalization of the Grace Theorem. The Journal of the Indian Mathematical Society, [S. l.], v. 84, n. 3-4, p. 269–272, 2017. DOI: 10.18311/jims/2017/6117. Disponível em: https://www.informaticsjournals.com/index.php/jims/article/view/6117. Acesso em: 3 may. 2024.