Helfferich, K. (1921). Georg von Siemens. Springer.
Chicago Style (17th ed.) CitationHelfferich, Karl. Georg Von Siemens. Berlin: Springer, 1921.
MLA (8th ed.) CitationHelfferich, Karl. Georg Von Siemens. Springer, 1921.
Warning: These citations may not always be 100% accurate.