Linkage between Purchase Order and AP Invoice number

 Hi, need some help. Client wants to know the best place to view the linkages between a  Purchase Order and AP invoice number, other than Supplier Ledger Inquiry. Most of the jobs client undertake are cost reimbursable and they need to see which PO’s have been receipted and the invoice numbers and requisition numbers which correlate to them (as they obtain copies of the received and paid invoices for client invoicing)

She don’t want to have to go into each purchase order and view the invoice number as it is too time consuming (i.e. the option is she chooses to use Supplier Ledger Inquiry). Thank you.