@misc{Boratyński_Adam_Betula_1980,
 author={Boratyński, Adam},
 copyright={Creative Commons Attribution BY-SA 4.0 license},
 howpublished={online},
 year={1980},
 title={Betula papyrifera Marshall},
 type={Image},
 URL={http://www.rcin.org.pl/Content/206400/PDF/KOR001_226342_Betula%20papyrifera%20Marsh.pdf},
 keywords={fruit structure, paper birch},
}