@misc{Bugajska-Jaszczołt_Beata_Some_2007,
 author={Bugajska-Jaszczołt, Beata and Czajkowska, Monika},
 type={artykuł},
 publisher={Wydawnictwo Akademii im. Jana Długosza w Częstochowie},
 title={Some aspects of teaching the concepts: arithmetic and weighted means at various levels of mathematicl education},
 address={Częstochowa},
 year={2007},
 language={eng},
}