TY  - JOUR
AU  - Achter, Jeffrey D.
TI  - Exceptional Covers of Surfaces
JO  - Canadian mathematical bulletin
PY  - 2010
SP  - 385
EP  - 393
VL  - 53
IS  - 3
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CMB-2010-049-7/
DO  - 10.4153/CMB-2010-049-7
ID  - 10_4153_CMB_2010_049_7
ER  -