ZHANG, Qiang and ZHAO, Xuezhi. Fixed point indices and fixed words at infinity of selfmaps of graphs II. Topological Methods in Nonlinear Analysis. Online. 26 February 2023. Vol. 61, no. 1, pp. 257 - 267. [Accessed 26 March 2026]. DOI 10.12775/TMNA.2022.007.