@misc{Friderich_Carl_Gottlob_(1814–1898)_Naturgeschichte_1923,
 author={Friderich, Carl Gottlob (1814–1898) and Bau, Alexander (1853–1926). Opracowanie.},
 copyright={Public Domain},
 address={Stuttgart},
 howpublished={online},
 year={1923},
 publisher={E. Schweizerbart'sche Verlagsbuchhandlung (Erwin Nägele)},
 language={ger},
 title={Naturgeschichte der Vögel Europas},
 type={Text},
 URL={http://www.rcin.org.pl/Content/205705/PDF/WA488_234524_19881_Bau-Voegel-Europas.pdf},
}