Cita APA (7th ed.)

Held, G. (1996). Understanding Data communications (4th.). P H I.

Cita Chicago (17th ed.)

Held, Gilbert. Understanding Data Communications. 4th. New Delhi: P H I, 1996.

Cita MLA (9th ed.)

Held, Gilbert. Understanding Data Communications. 4th. P H I, 1996.