Maistrenko, T. Yu., and S. V. Popovich. 2001. “$C*$-Algebras Associated With $F_{2^n }$ Unimodal Dynamical Systems”. Ukrains’kyi Matematychnyi Zhurnal 53 (7), 929-38. https://umj.imath.kiev.ua/index.php/umj/article/view/4314.