@article{AUCMP_1990__31_2_a7,
     author = {Kholshchevnikova, N. N.},
     title = {On concentrated sets and {N-sets}},
     journal = {Acta Universitatis Carolinae. Mathematica et Physica},
     pages = {47--50},
     publisher = {mathdoc},
     volume = {31},
     number = {2},
     year = {1990},
     mrnumber = {1101414},
     zbl = {0795.03066},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/item/AUCMP_1990__31_2_a7/}
}