@misc{Schwering_Karl_(1846–1925)_Handbuch_1907,
 author={Schwering, Karl (1846–1925)},
 copyright={Public Domain},
 address={Leipzig},
 address={Berlin},
 howpublished={online},
 year={1907},
 publisher={B. G. Teubner},
 language={ger},
 type={Text},
 title={Handbuch der Elementarmathematik für Lehrer},
 URL={http://rcin.org.pl/impan/Content/67918/PDF/WA35_18216_7091_Handbuch.pdf},
}