- Yaokun Wu, Zeying Xu, Yinfeng Zhu, “A five-element transformation monoid on labelled trees”, European Journal of Combinatorics, 80, 2019, 401
- Eugene Shragowitz, Rung-Bin Lin, “Combinatorial optimization by stochastic automata”, Ann Oper Res, 22, no. 1, 1990, 293