@book{PPN309767830, title = {Die Geometrie der Lage 2. Abth.}, series = {GDML\_Books}, year = {1868}, language = {ger}, url = {http://dml.mathdoc.fr/item/PPN309767830} }
(éd.). Die Geometrie der Lage 2. Abth.. GDML_Books (1868), http://gdmltest.u-ga.fr/item/PPN309767830/