TY  - JOUR
AU  - R. I. Grigorchuk
TI  - On the topological and metric types of surfaces regularly covering a~closed surface
JO  - Izvestiya. Mathematics 
PY  - 1990
SP  - 517
EP  - 553
VL  - 34
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_1990_34_3_a1/
LA  - en
ID  - IM2_1990_34_3_a1
ER  -