Columbia subject headings:
Netherlands--Politics and government--1556-1648.
Netherlands--Politics and government--1648-1795.
Official secrets--Netherlands--History.
Harvard subject headings:
Netherlands--Politics and government--1556-1648.
Netherlands--Politics and government--1648-1795.
Official secrets--Netherlands--History.
Princeton subject headings:
Netherlands--History--1648-1795.
Netherlands--History--Eighty Years' War, 1568-1648.
Netherlands--Politics and government--1556-1647.
Netherlands--Politics and government--1647-1795.