@article{10_4064_cm_37_1_29_34,
     author = {A. Kucia and A. Szyma\'nski},
     title = {There are absolute ultrafilters on {N} which are not minimal},
     journal = {Colloquium Mathematicum},
     pages = {29--34},
     publisher = {mathdoc},
     volume = {37},
     number = {1},
     year = {1971},
     doi = {10.4064/cm-37-1-29-34},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-37-1-29-34/}
}