APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

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