@misc{Wittstein_Theodor_(1816–1894)_Lehrbuch_1874, author={Wittstein, Theodor (1816–1894)}, copyright={Public Domain}, address={Hannover}, howpublished={online}, year={1874}, publisher={Hahn'nche Hofbuchhandlung}, language={ger}, title={Lehrbuch der Elementar-Mathematik. 2 Bd., 2 Abt., Stereometrie}, type={Text}, }