@misc{_Acta_1991,
 volume={Vol. 33},
 number={1/2},
 copyright={Creative Commons Attribution BY 3.0 PL license},
 address={Kraków},
 journal={Acta Hydrobiologica},
 howpublished={online},
 year={1991},
 publisher={Institute of Freshwater Biology of the Polish Academy of Sciences},
 language={eng},
 title={Acta Hydrobiologica Vol. 33 Fasc. 1/2 (1991)},
 type={Text},
}