APA (7th ed.) Citation

Johnston, A. (2001). SIP: Understanding the session initiation protocol. Artech House.

Chicago Style (17th ed.) Citation

Johnston, Alan. SIP: Understanding the Session Initiation Protocol. Boston, Mass. [u.a.]: Artech House, 2001.

MLA (9th ed.) Citation

Johnston, Alan. SIP: Understanding the Session Initiation Protocol. Artech House, 2001.

Warning: These citations may not always be 100% accurate.