@book{PPN615467385, title = {Differential-Rechnung Theil 1}, series = {GDML\_Books}, publisher = {Helwing}, address = {Hannover}, year = {1888}, language = {de}, url = {http://dml.mathdoc.fr/item/PPN615467385} }
Stegemann, Max. Differential-Rechnung Theil 1. GDML_Books (1888), http://gdmltest.u-ga.fr/item/PPN615467385/