@misc{Ostański_Mariusz_Twenty_2002,
 author={Ostański, Mariusz and Kościelny, Henryk and Profus, Piotr},
 volume={58},
 number={4},
 copyright={Creative Commons Attribution BY 3.0 PL license},
 address={Kraków},
 journal={Let's protect Our Indigenous Nature},
 howpublished={online},
 year={2002},
 publisher={Institute of Nature Conservation of the Polish Academy of Sciences},
 language={pol},
 type={Text},
 title={Twenty years of the activity of the Katowice branch of the Ornithological Section of the Polish Zoological Association},
 URL={http://www.rcin.org.pl/Content/198111/PDF/KR038_193913_r2002-t58-no4_ChPO-Ostanski-80-85.pdf},
}