@misc{Hawro_Justyna_About_2007,
 author={Hawro, Justyna},
 type={artykuł},
 publisher={Wydawnictwo Akademii im. Jana Długosza w Częstochowie},
 title={About some difficulties in doing proofs encountered by the students from the first year of mathematics},
 address={Częstochowa},
 year={2007},
 language={eng},
}