@article{10_14712_1213_7243_015_110,
     author = {Selker, Kevin},
     title = {Ideal independence, free sequences, and the ultrafilter number},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {117--124},
     publisher = {mathdoc},
     volume = {56},
     number = {1},
     year = {2015},
     doi = {10.14712/1213-7243.015.110},
     mrnumber = {3311582},
     zbl = {06433810},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.14712/1213-7243.015.110/}
}