HINKKANEN, A. Sense-reversing generators of discrete convergence groups in the plane. Annales Fennici Mathematici, [S. l.], v. 16, n. 1, p. 179–182, 1991. DOI: 10.5186/aasfm.1991.1612. Disponível em: https://afm.journal.fi/article/view/134714. Acesso em: 25 nov. 2024.