TY  - JOUR
AU  - A. V. Chechkin
TI  - Ultraoperators in the theory of information systems
JO  - Doklady Akademii Nauk
PY  - 1982
SP  - 302
EP  - 305
VL  - 263
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1982_263_2_a11/
LA  - ru
ID  - DAN_1982_263_2_a11
ER  -