@book{PPN587689242, title = {Planimetrie und ebene Trigonometrie Theil 1}, series = {GDML\_Books}, publisher = {Teubner}, address = {Leipzig}, year = {1874}, language = {de}, url = {http://dml.mathdoc.fr/item/PPN587689242} }
Schlömilch, Oskar. Planimetrie und ebene Trigonometrie Theil 1. GDML_Books (1874), http://gdmltest.u-ga.fr/item/PPN587689242/