@misc{Danielewicz_Władysław_The_1990,
 author={Danielewicz, Władysław},
 volume={46},
 editor={Research Centre for the Protection of Nature and Natural Resources of the Polish Academy of Sciences},
 number={4-5},
 copyright={Creative Commons Attribution BY 3.0 PL license},
 address={Warszawa},
 address={Kraków},
 journal={Let's protect Our Indigenous Nature},
 howpublished={online},
 year={1990},
 publisher={Państwowe Wydawnictwo Naukowe},
 language={pol},
 type={Text},
 title={The occurence of the black birch, Betula obscura, in the Ojców National Park},
 URL={http://www.rcin.org.pl/Content/84548/PDF/KR038_102727_r1990-t46-no4-5_ChPO-Danielewicz-45-51.pdf},
 keywords={Ojców National Park (Ojców, Poland), black birch, Betula obscura},
}