TY  - JOUR
AU  - V. A. Koibaev
TI  - On a question about generalized congruence subgroups. I
JO  - Zapiski Nauchnykh Seminarov POMI
PY  - 2018
SP  - 105
EP  - 110
VL  - 470
UR  - http://geodesic.mathdoc.fr/item/ZNSL_2018_470_a5/
LA  - ru
ID  - ZNSL_2018_470_a5
ER  -