@article{PPN62264663X+DMDLOG_0003, title = {Ebene Trigonometrie. Stereometrie.}, booktitle = {Leitfaden der Elementar-Mathematik Teil 2}, series = {GDML\_Books}, publisher = {Schmidt}, address = {Helmstedt}, year = {1883}, pages = {15}, url = {http://dml.mathdoc.fr/item/PPN62264663X+DMDLOG_0003} }
(éd.). Ebene Trigonometrie. Stereometrie., dans Leitfaden der Elementar-Mathematik Teil 2, GDML_Books, (1883), p. 15. http://gdmltest.u-ga.fr/item/PPN62264663X+DMDLOG_0003/