@misc{Kovacik_Stefan_Coefficients_2007,
 author={Kovacik, Stefan},
 type={artykuł},
 publisher={Wydawnictwo Akademii im. Jana Długosza w Częstochowie},
 title={Coefficients of learning in mathematical and nonmathematical subject matter},
 address={Częstochowa},
 year={2007},
 language={eng},
}