@misc{Erritzoe_Johannes_Tree,
 author={Erritzoe, Johannes},
 howpublished={online},
 publisher={Zielona Góra: University of Zielona Góra, Faculty of Biological Sciences},
 language={eng},
 title={Tree sparrows foraging on elm seeds for more than a month},
 type={artykuł},
 keywords={wróblowe, ornitologia},
}