ZDUN, Marek Cezary; LEŚNIAK, Zbigniew. On iteration groups of singularity-free homeomorphisms of the plane. Annales Mathematicae Silesianae, [S. l.], v. 8, p. 203–210, 1994. Disponível em: https://journals.us.edu.pl/index.php/AMSIL/article/view/14235. Acesso em: 18 apr. 2025.