Cita APA (7th ed.)

Ralphs, J. D. (1985). Principles and practice of multi-frequency telegraphy. P. Peregrinus on behalf of the Institution of Electrical Engineers.

Cita Chicago (17th ed.)

Ralphs, J. D. Principles and Practice of Multi-frequency Telegraphy. London, UK: P. Peregrinus on behalf of the Institution of Electrical Engineers, 1985.

Cita MLA (8th ed.)

Ralphs, J. D. Principles and Practice of Multi-frequency Telegraphy. P. Peregrinus on behalf of the Institution of Electrical Engineers, 1985.