Biswas, N. N. (1964). Principles of telegraphy. Media promoters & Publishers.
Cita Chicago (17th ed.)Biswas, Nripendra N. Principles of Telegraphy. New Delhi: Media promoters & Publishers, 1964.
Cita MLA (9th ed.)Biswas, Nripendra N. Principles of Telegraphy. Media promoters & Publishers, 1964.
Atenció: Aquestes cites poden no estar 100% correctes.