If we are talking about looking up a bean by its JNDI name, it should be something in this format:
java:global[/application name]/module name/enterprise bean name[/interface name]
where application name is the name of the .ear, module name is the name of .war or .jar file, where bean name is the name of the bean class and interface name is the interface of the bean if any.
reference:http://docs.oracle.com/javaee/6/tutorial/doc/gipjf.html
For environment entries lookup, you define values of environment entries in the deployment descriptor and the bean can inject the values of environment entries using @Resource.
For more example, please refer to Fritz's notes session 7.8