TY  - JOUR
AU  - L. Yu. Devyatkin
TI  - The set of closed classes $P_{k+1}$ that can be homomorphically mapped on $P_k$ has the cardinality of continuum
JO  - Vestnik Moskovskogo universiteta. Matematika, mehanika
PY  - 2020
SP  - 69
EP  - 70
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/VMUMM_2020_1_a10/
LA  - ru
ID  - VMUMM_2020_1_a10
ER  -