Black, Uyless. Computer Networks, Protocols, Standards, and Interfaces (2nd edition). Englewood Cliffs, N.J.: Prentice Hall, 1993.

Black, Uyless. Data Link Protocols. Englewood Cliffs, N.J.: Prentice Hall, 1993.

Deasington, R.J. X.25 Explained: Protocols for Packet Switching Networks (2nd edition). Ellis Horwood: New York 1985.

Piscitello, David M. and Chlapin, A. Lyman. Open Systems Networking TCP/IP and OSI. Addison-Wesley Publishing Company, 1993.

Stallings, William ISDN and Broadband ISDN with Frame Relay and ATM (3rd edition). Englewood Cliffs, N.J.: Prentice Hall, 1995.

Tannenbaum, Andrew S. Computer Networks (2nd edition). Englewood Cliffs, N.J.: Prentice-Hall, 1988.

CCITT Recommendation X.25 (Blue Book, Volume VIII, Melbourne, 1988.) This is the definitive reference for X.25, and contains details on packet formats and user facilities.

ITU CCITT Recommendation Q.922, ISDN Data Link Layer Specification for Frame Mode Bearer Services, Geneva 1992.

ANSI T1.617, Integrated Services Digital Networks (ISDN)- Signaling Specification for Frame Relay Bearer Service for Digital Subscriber Signaling System Number 1 (DSS1), 1991.

ANSI T1.617a, Integrated Services Digital Networks (ISDN)- Signaling Specification for Frame Relay Bearer Service for Digital Subscriber Signaling System Number 1 (DSS1), (Protocol encapsulation and PICS), 1994. This document contains the Annex C, D, E, F, G, H

Cooper & Associates PC-based X.25 training: TeletutorTM: X.25 in Modern Data Communications. This software runs on an IBM PC and can be ordered directly from Advanced Relay Corporation.