TARCHAŁA, Katarzyna; WALCZAK, Paweł. Multi ping-pong and an entropy estimate in groups. Annales Mathematicae Silesianae, [S. l.], v. 32, p. 313–318, 2018. Disponível em: https://journals.us.edu.pl/index.php/AMSIL/article/view/13929. Acesso em: 12 apr. 2025.