TY  - JOUR
AU  - Mátrai, Tamás
TI  - Covering $\Sigma^0_\xi$-generated ideals by $\Pi^0_\xi$ sets
JO  - Commentationes Mathematicae Universitatis Carolinae
PY  - 2007
SP  - 245
EP  - 268
VL  - 48
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMUC_2007__48_2_a6/
LA  - en
ID  - CMUC_2007__48_2_a6
ER  -