@misc{Haeckel_Ernst_(1834-1919)_Berol.,
 author={Haeckel, Ernst (1834-1919)},
 howpublished={online},
 language={ger},
 type={rękopis},
 title={Berol. Ms. Autographen-Sammlung, Haeckel},
 keywords={W. von Unwerth},
}