@misc{_Protection_1952,
 volume={R. 20},
 copyright={Creative Commons Attribution BY 3.0 PL license},
 address={Kraków},
 journal={Protection of Nature},
 howpublished={online},
 year={1952},
 publisher={Nature Protection Committee of the Polish Academy of Sciences and Lettres},
 language={pol},
 title={Protection of Nature Ann. 20 (1952)},
 type={Text},
}