@article{05934323, title = {Commensurator subgroups of surface groups.}, journal = {Revista Colombiana de Matem\'aticas}, volume = {44}, year = {2010}, pages = {1-13}, zbl = {1223.57002}, language = {en}, url = {http://dml.mathdoc.fr/item/05934323} }
Ocampo Uribe, Oscar Eduardo. Commensurator subgroups of surface groups.. Revista Colombiana de Matemáticas, Tome 44 (2010) pp. 1-13. http://gdmltest.u-ga.fr/item/05934323/