Columbia subject headings:
Harvard subject headings:
Internal security--Northern Ireland--History.
Northern Ireland--Politics and government.
Northern Ireland--Social conditions.
Peace movements--Northern Ireland--History.
Police--Northern Ireland--History.
Political violence--Northern Ireland
Princeton subject headings:
Internal security--Northern Ireland--History.
Northern Ireland--Politics and government.
Northern Ireland--Social conditions.
Peace movements--Northern Ireland--History.
Police--Northern Ireland--History.
Political violence--Northern Ireland.