@misc{Klasa_Anna_The_1991,
 author={Klasa, Anna},
 volume={47},
 number={1-2},
 copyright={Creative Commons Attribution BY 3.0 PL license},
 address={Kraków},
 journal={Let's protect Our Indigenous Nature},
 howpublished={online},
 year={1991},
 publisher={Research Centre for the Protection of Nature and Natural Resources of the Polish Academy of Sciences},
 language={pol},
 type={Text},
 title={The plant and animal species introduced in the Ojców National Park in the last two decades},
 URL={http://www.rcin.org.pl/Content/68902/PDF/KR038_87867_r1991-t47-no1-2_ChPO-Klasa-19-27.pdf},
 keywords={introduction, Ojców National Park (Ojców, Poland)},
}