@book{PPN597844887, title = {Die Elementar-Geometrie Bd. 1,3}, series = {GDML\_Books}, publisher = {Dalp}, address = {Leipzig}, year = {1839}, language = {de}, url = {http://dml.mathdoc.fr/item/PPN597844887} }
Francoeur, Louis Benjamin. Die Elementar-Geometrie Bd. 1,3. GDML_Books (1839), http://gdmltest.u-ga.fr/item/PPN597844887/