Akin, E., S. Plaskacz, and J. Zwierzchowska. “Smale Strategies for the N-Person Iterated prisoner’s Dilemma”. Topological Methods in Nonlinear Analysis, vol. 53, no. 1, Feb. 2019, pp. 351-6, https://apcz.umk.pl/TMNA/article/view/TMNA.2019.001.