How To Find All The Oracle API's For Any Module

Script to find all the Oracle API's for any particular  module:

SELECT   SUBSTR (a.owner, 1, 20), SUBSTR (a.NAME, 1, 30),

         SUBSTR (a.TYPE, 1, 20), SUBSTR (u.status, 1, 10) stat,

         u.last_ddl_time, SUBSTR (text, 1, 80) description

    FROM dba_source a, dba_objects u

   WHERE 2 = 2

     AND u.object_name = a.NAME

     AND a.text LIKE '%Header%'

     AND a.TYPE = u.object_type

     AND a.NAME LIKE 'AP_%API%'     -- This is AP Related           

ORDER BY a.owner, a.NAME