@book{PPN380673029, title = {Methoden der mathematischen Physik Bd. 2}, series = {GDML\_Books}, year = {1937}, zbl = {0017.39702}, language = {ger}, url = {http://dml.mathdoc.fr/item/PPN380673029} }
(éd.). Methoden der mathematischen Physik Bd. 2. GDML_Books (1937), http://gdmltest.u-ga.fr/item/PPN380673029/