http://www.oracle.com/technology/obe/obe1013jdev/10131/10131_ejb_30/ejb_30.htm   

http://java.sun.com/developer/onlineTraining/Beans/EJBTutorial/           

http://www.comptechdoc.org/docs/kanti/ejb/statefullvsstateless.html      Stateful versus Stateless EJBs. Dr. Kanti Prasad has done an excellent work in presenting J2EE architecture in the associated presentation.

http://www.academictutorials.com/ejb/ejb-container.asp       

http://www.roseindia.net/javabeans/javabeans.shtml                     

http://www.techinterviews.com/ejb-interview-questions