@misc{Haeckel_Ernest_(1834–1919)_Die_1899,
 author={Haeckel, Ernest (1834–1919)},
 copyright={Public Domain},
 address={Bonn},
 howpublished={online},
 year={1899},
 publisher={Emil Strauss},
 language={ger},
 title={Die Welträthsel : Gemeinverständliche Studien über Monistiche Philosophie},
 type={Text},
 URL={http://rcin.org.pl/Content/1655/PDF/WA488_3720_956_Haeckel-Weltratsel.pdf},
 keywords={Monism, Evolution, Religion and science},
}