Residual Finiteness of Surface Groups

John Hempel
1972 Proceedings of the American Mathematical Society  
It is known [2] that free groups, and more generally fundamental groups of 2-manifolds [1], are residually finite. We give here an elementary proof of these facts.
doi:10.2307/2038357 fatcat:d46wzyx5uvhbxgxulrp4wzw2oe