AGATA, Sebastian. Free groups of rotations acting without fixed points on the rational unit sphere. Scientia Series A: Mathematical Sciences, [S. l.], v. 16, p. 109–117, 2008. DOI: 10.71712/. Disponível em: https://revistas.usm.cl/scientia/article/view/115.. Acesso em: 7 jun. 2025.