@article{CMUC_1988__29_1_a15,
     author = {Nelson, Evelyn and Ad\'amek, Ji\v{r}{\'\i} and Jung, A. and Reiterman, Jan and Tarlecki, Andrzej},
     title = {Comparison of subset systems},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {169--177},
     publisher = {mathdoc},
     volume = {29},
     number = {1},
     year = {1988},
     mrnumber = {937559},
     zbl = {0657.06009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1988__29_1_a15/}
}