1. M. Handley, H. Schulzrinne, E. Schooler, J. Rosenberg: SIP: Session Initiation Protocol. Internet Engineering Task Force RFC 2543, March 1999
2. Parlay API Specification 1.2, User Guide. http://www.parlay.org, Sept. 1999
3. J. Lennox, H. Schulzrinne: CPL: A Language for User Control of Internet Telephony Services, Internet Draft, Internet Engineering Task Force, March 2000.
4. H. Schulzrinne, S. Casner, R. Frederick, V. Jacobson: RTP: a transport protocol for real-time applications. Internet Engineering Task Force RFC 1889, Jan. 1996
5. C. Gbaguidi, et al, Integration of Internet and telecommunications: An Architecture for Hybrid Services. IEEE JSAC vol. 17, no. 9, Sept. 1999