@misc{Jędrzejewski_Jacek_On_2007,
 author={Jędrzejewski, Jacek},
 type={artykuł},
 publisher={Wydawnictwo Akademii im. Jana Długosza w Częstochowie},
 title={On objective and subjective difficulties in understanding the notions of the least upper bound and the greatest lower bound},
 address={Częstochowa},
 year={2007},
 language={eng},
}