TY  - JOUR
AU  - Yu. L. Ershov
TI  - The upper semilattice of numerations of a finite set
JO  - Algebra i logika
PY  - 1975
SP  - 258
EP  - 284
VL  - 14
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/AL_1975_14_3_a1/
LA  - ru
ID  - AL_1975_14_3_a1
ER  -