how can I get a report showing all the expense reports unapproved by the manager?

Hi,
I need a pl/sql query which shows all the expense reports not yet approved by the respective managers of the traveler.
The below query give an output with duplicates. All the expense reports are double. Please help me in correcting this.

select p.full_name traveller,
       a.invoice_num,
       a.creation_date,
       a.report_submitted_date,
       a.employee_id,
       a.expense_status_code
  from ap.ap_expense_report_headers_all a, per_all_people_f p
 where a.expense_status_code = 'PENDMGR'
   and a.employee_id = p.person_id
 order by a.report_submitted_date
select * from ap_expense_report_headers_all