@book{PPN380672502, title = {Methoden der mathematischen Physik Bd. 1}, series = {GDML\_Books}, year = {1924}, zbl = {50.0335.07}, language = {ger}, url = {http://dml.mathdoc.fr/item/PPN380672502} }
(éd.). Methoden der mathematischen Physik Bd. 1. GDML_Books (1924), http://gdmltest.u-ga.fr/item/PPN380672502/