Cita APA (7a ed.)

Bellamy, J. (1991). Digital telephony (2nd ed.). John Wiley & Sons.

Cita Chicago Style (17a ed.)

Bellamy, John. Digital Telephony. 2nd ed. New York [etc.]: John Wiley & Sons, 1991.

Cita MLA (9a ed.)

Bellamy, John. Digital Telephony. 2nd ed. John Wiley & Sons, 1991.