1. Gryphon web site. http://www.research.ibm.com/gryphon/ .
2. Publish/subscribe. http://en.wikipedia.org/wiki/Publish/subscribe .
3. Sun microsystems. Java Message Service API, Sun Microsystems. 2003.
4. Vitria. http://www.vitria.com/ .
5. Object management group. corba notification service specification, version 1.0.1. omg document formal/2002-08-04, 2002.