fr_document_number,regs_document_id
06-6640,EPA-HQ-OAR-2006-0536-0001
06-6640,EPA-HQ-OAR-2006-0537-0001
06-6640,EPA-HQ-OAR-2006-0538-0001
06-6640,EPA-HQ-OAR-2006-0672-0001