Oracle Applications - Query to get all responsibilities assigned to all active users

select  distinct responsibility_name ,y.user_name
       ,y.description
      , z.employee_number
      , z.full_name,
       z.first_name,
       z.last_name
        from apps.fnd_user_resp_groups x , fnd_user y , per_people_f z ,fnd_responsibility_tl a
              where x.responsibility_id = a.responsibility_id    
    and  x.start_date <=sysdate and (x.end_date is null OR x.end_date > sysdate)
    and y.user_id = x.user_id
    and  y.start_date <=sysdate and (y.end_date is null OR y.end_date > sysdate)
    and z.employee_number = y.user_name
    and  z.effective_start_date <=sysdate
    and (z.effective_end_date  > sysdate or z.effective_end_date is NULL)
    and language = 'US'
    order by employee_number nulls first