TY - JOUR AU - Winkelmann, Jörg TI - Realizing countable groups as automorphism groups of Riemann surfaces JO - Documenta mathematica PY - 2001 SP - 413 EP - 417 VL - 6 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DOCMA_2001__6__a6/ LA - en ID - DOCMA_2001__6__a6 ER -