Bellamy, John C. Digital Telephony / John C. Bellamy. - 3rd ed. - New Delhi : Wiley, c2000 [Reprint 2017]. - xxv, 643 p. : ill. ; 23 cm. Includes index ISBN: 9788126509294 Subjects--Topical Terms: Digital telephone systems Dewey Class. No.: 621.385 / BED 2000