@article{BUMI_1964_3_19_2_a8,
     author = {Cullen, Helen F.},
     title = {A characterization of sets of cardinal \ensuremath{\leq} {C}},
     journal = {Bollettino della Unione matematica italiana},
     pages = {138--140},
     publisher = {mathdoc},
     volume = {Ser. 3, 19},
     number = {2},
     year = {1964},
     zbl = {0163.25003},
     mrnumber = {174485},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/BUMI_1964_3_19_2_a8/}
}