Link between purchase Order and Requisition

SELECT prh.segment1 req_number,
       prh.authorization_status,
       prl.line_num req_line_num,
       prl.item_description req_item_description,
       prl.unit_price req_unit_price,
       prl.quantity req_quantity,
       pd.req_header_reference_num,
       pd.req_line_reference_num,
       pl.line_num,
       pl.item_description,
       pl.quantity,
       pl.amount,
       ph.segment1 po_number,
       prd.distribution_id,
       pd.req_distribution_id
  FROM po_requisition_headers_all prh,
       po_requisition_lines_all   prl,
       po_req_distributions_all   prd,
       po_distributions_all       pd,
       po_line_locations_all      pll,
       po_lines_all               pl,
       po_headers_all             ph
 WHERE prh.requisition_header_id = prl.requisition_header_id
   and prh.org_id = prl.org_id
   and prl.requisition_line_id = prd.requisition_line_id
   and prl.org_id = prd.org_id
   and prd.distribution_id = pd.req_distribution_id(+)
   and prd.org_id = pd.org_id(+)
   and pd.line_location_id = pll.line_location_id(+)
   and pd.org_id = pll.org_id(+)
   and pll.po_line_id = pl.po_line_id(+)
   and pll.org_id = pl.org_id(+)
   and pl.po_header_id = ph.po_header_id(+)
   and pl.org_id = ph.org_id(+)