source: All relevant documents  must have the purchase order number quoted, without which, Buyer's accounts payable department will reject and return the invoices.
target: All relevant documents must have the purchase order number quoted. If they do not have this, Buyer's accounts payable department will reject and return the invoices.
references: All relevant documents must have the purchase order number quoted. If they do not have this, Buyer's accounts payable department will reject and return the invoices.