Sukretniy, K., and E. Jushenko. “On $*$-Wildness of a Free Product of Finite-Dimensional $C^*$-Algebras”. Methods of Functional Analysis and Topology 12, no. 2 (June 25, 2006): 151–156. Accessed December 16, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/309.