@book{PPN593049519, title = {Zw\"olf Kupfertafeln zu dem Lehrbuch der descriptiven Geometrie Taf}, series = {GDML\_Books}, publisher = {Metzler}, address = {Stuttgart}, year = {1857}, language = {de}, url = {http://dml.mathdoc.fr/item/PPN593049519} }
Gugler, Bernhard. Zwölf Kupfertafeln zu dem Lehrbuch der descriptiven Geometrie Taf. GDML_Books (1857), http://gdmltest.u-ga.fr/item/PPN593049519/