@misc{Balcar_Bohuslav_(1943–_)_Ultrafilters_1979,
 author={Balcar, Bohuslav (1943– )},
 volume={27},
 editor={Frankiewicz, Ryszard},
 editor={Polska Akademia Nauk.},
 editor={Państwowe Wydawnictwo Naukowe (1951–1992)},
 number={7-8},
 copyright={Rights Reserved - Restricted Access},
 address={Varsovie},
 howpublished={online},
 year={1979},
 publisher={Państwowe Wydawnictwo Naukowe},
 language={eng},
 type={Text},
 title={Ultrafilters and ω1-points in βN\N},
}