TY  - JOUR
AU  - Balcerzak, Marek
TI  - On isomorphisms between $\sigma$-ideals on $\omega_1$
JO  - Commentationes Mathematicae Universitatis Carolinae
PY  - 1990
SP  - 743
EP  - 749
VL  - 31
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMUC_1990__31_4_a13/
LA  - en
ID  - CMUC_1990__31_4_a13
ER  -