@misc{_Acta_1991,
 volume={26},
 number={2},
 editor={Polska Akademia Nauk. Instytut Zoologii},
 address={Warszawa},
 journal={Acta Ornithologica},
 howpublished={online},
 year={1991},
 publisher={Instytut Zoologii PAN},
 language={pol},
 language={eng},
 language={rus},
 type={Text},
 title={Acta Ornithologica, vol. 26 no 2 (1991)},
 keywords={ornithology, birds, Poland, periodicals},
}