@book{PPN592283267, title = {Planimetrie Bd. 1, Abth. 2}, series = {GDML\_Books}, publisher = {Hahn}, year = {1877}, language = {de}, url = {http://dml.mathdoc.fr/item/PPN592283267} }
Wittstein, Theodor. Planimetrie Bd. 1, Abth. 2. GDML_Books (1877), http://gdmltest.u-ga.fr/item/PPN592283267/