Remarks on the Cobordism Group of Surface Diffeomorphisms. A.L. Edmonds, J.H. Ewing (1982) Mathematische Annalen
Representations of orbifold groups and parabolic bundles. Hans U. Boden (1991) Commentarii mathematici Helvetici
Residual Finiteness of Surface Groups via Tessellations. L.M. Lopez (1994) Discrete & computational geometry