@misc{_Acta_1991,
 editor={Polska Akademia Nauk. Instytut Zoologii},
 address={Warszawa},
 journal={Acta Ornithologica},
 howpublished={online},
 year={1991},
 publisher={Instytut Zoologii PAN},
 language={eng},
 language={pol},
 language={rus},
 type={Text},
 title={Acta Ornithologica, vol. 26 (1991)},
 keywords={Poland, birds, periodicals, ornithology},
}