APA (7th ed.) Citation

Lehnert, J. (1974). Introduction to telegraph engineering (2nd ed.). Siemens].

Chicago Style (17th ed.) Citation

Lehnert, Josef. Introduction to Telegraph Engineering. 2nd ed. [Berlin: Siemens], 1974.

MLA (9th ed.) Citation

Lehnert, Josef. Introduction to Telegraph Engineering. 2nd ed. Siemens], 1974.