List of unreferenced objects I need a list of unreferenced objects, that is, objects that neither have any reference with other objects nor are used in any API (Oracle stored procedures).  

This is required for reducing and resizing database size.

Please help me to find a list of these objects.
You need to query DBA_DEPENDENCIES.   But be aware of references that may exist outside of the database itself - references in sql scripts on some user's workstation, or in application code that is not a stored procedure.