Pinsky, T., and B. Wajnryb. “Dynamics of Shear Homeomorphisms of Tori and the Bestvina-Handel Algorithm”. Topological Methods in Nonlinear Analysis, vol. 39, no. 1, Apr. 2012, pp. 119-50, https://apcz.umk.pl/TMNA/article/view/TMNA.2012.008.