Columbia subject headings:
Italy, Southern--Foreign relations--Spain.
Italy--Foreign relations--1559-1789.
Spain--Foreign relations--1516-1700.
Spain--Foreign relations--18th century.
Spain--Foreign relations--Italy, Southern.
Harvard subject headings:
Italy, Southern--Foreign relations--Spain.
Spain--Foreign relations--Italy, Southern.
Princeton subject headings:
Italy, Southern--Foreign relations--Spain--Congresses.
Spain--Foreign relations--Italy, Southern--Congresses.