@misc{Wolff_Franz_(1858–1931)_Lehrbuch_1853,
 author={Wolff, Franz (1858–1931)},
 copyright={Public Domain},
 address={Berlin},
 howpublished={online},
 year={1853},
 publisher={Georg Reimer},
 language={ger},
 title={Lehrbuch der Geometrie. 2 Theil, Stereometrie und sphärische Trigonometrie},
 type={Text},
 URL={http://rcin.org.pl/Content/70104/PDF/WA35_12546_7247-II_Lehrbuch.pdf},
}