TY  - JOUR
AU  - E. Z. Dyment
TI  - Exact bounds of denumerable collections of degrees of difficulty
JO  - Matematičeskie zametki
PY  - 1980
SP  - 899
EP  - 910
VL  - 28
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZM_1980_28_6_a8/
LA  - ru
ID  - MZM_1980_28_6_a8
ER  -