@misc{Czekalski_Mieczysław_The_1988,
 author={Czekalski, Mieczysław},
 volume={44},
 editor={Research Centre for the Protection of Nature and Natural Resources of the Polish Academy of Sciences},
 number={3},
 copyright={Creative Commons Attribution BY 3.0 PL license},
 address={Warszawa},
 address={Kraków},
 journal={Let's protect Our Indigenous Nature},
 howpublished={online},
 year={1988},
 publisher={Państwowe Wydawnictwo Naukowe},
 language={pol},
 type={Text},
 title={The birch trees of Betula verrucosa are worthy of protection},
 URL={http://rcin.org.pl/Content/84476/PDF/KR038_100177_r1988-t44-no3_ChPO-Czekalski-36-41.pdf},
 keywords={Betula verrucosa},
}