@misc{Bartkowiak_Stanisław_Within_1969,
 author={Bartkowiak, Stanisław},
 volume={14},
 editor={Zakład Dendrologii i Arboretum Kórnickie Polskiej Akademii Nauk},
 copyright={Creative Commons Attribution BY-SA 4.0 license},
 address={Poznań ; Warszawa},
 journal={Arboretum Kórnickie},
 howpublished={online},
 year={1969},
 publisher={Państwowe Wydawnictwo Naukowe},
 language={mul},
 type={Text},
 title={Within tree variability of leaf characters at three levels of the crown of European ash (Fraxinus excelsior L.)},
 keywords={Fraxinus excelsior, European ash, variability of leafs},
}