PHILLIPS, J. D. QUOTIENTS OF GROUPS. Tamkang Journal of Mathematics, [S. l.], v. 28, n. 4, p. 271-275, 1997. DOI: 10.5556/j.tkjm.28.1997.4304. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4304. Acesso em: 3 dec. 2021.