Посилання:Finite automaton actions of free products of groups / M. Fedorova, A. Oliynyk // Algebra and Discrete Mathematics. — 2017. — Vol. 23, № 2. — С. 230-236. — Бібліогр.: 4 назв. — англ.
It is shown that for groups G and H that act faithfully by finite state automorphisms on regular rooted trees their free product G∗H admits a faithful action by finite state automorphisms on some regular rooted tree.