Columbia subject headings:
Harvard subject headings:
Gilmour, Raymond.
Northern Ireland--History--1968-1998.
Provisional IRA.
Royal Ulster Constabulary--Biography.
Spies--Northern Ireland--Biography.
Terrorism--Northern Ireland--Prevention.
Undercover operations--Northern Ireland.
Princeton subject headings:
Gilmour, Raymond.
Northern Ireland--History--1968-1998.
Provisional IRA.
Spies--Northern Ireland--Biography.
Terrorism--Prevention--Northern Ireland.
Undercover operations--Northern Ireland.