TY  - JOUR
AU  - V. V. Ryzhikov
TI  - An estimate of the entropy of a class of $Z^2$-actions
JO  - Matematičeskie zametki
PY  - 1992
SP  - 152
EP  - 155
VL  - 51
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZM_1992_51_2_a22/
LA  - ru
ID  - MZM_1992_51_2_a22
ER  -