@article{MASLO_1987__37_1_a7,
     author = {Balcerzak, Marek},
     title = {Classification of $sigma$-ideals},
     journal = {Mathematica slovaca},
     pages = {63--70},
     publisher = {mathdoc},
     volume = {37},
     number = {1},
     year = {1987},
     mrnumber = {899018},
     zbl = {0611.28001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1987__37_1_a7/}
}