@article{SM_1978_34_6_a6,
     author = {I. I. Parovichenko},
     title = {On some questions connected with the iteration of set-theoretic operations},
     journal = {Sbornik. Mathematics},
     pages = {813--840},
     year = {1978},
     volume = {34},
     number = {6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1978_34_6_a6/}
}