Woryna, Adam. “The Group of Balanced Automorphisms of a Spherically Homogeneous Rooted Tree”. Annales Mathematicae Silesianae 23 (September 30, 2009): 83–101. Accessed May 8, 2025. https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14046.