Columbia subject headings:
Papal States--History--Sources--Congresses.
Romagna (Italy)--History--Sources--Congresses.
Harvard subject headings:
Archives--Italy--Romagna--Congresses.
Church and state--Italy--Romagna--History--Sources.
Papal States--History--1407-1605--Sources.
Papal States--History--1605-1799--Sources.
Papal States--History--Congresses.
Papal States. Legazione di Romagna--Archives.
Romagna (Italy)--Church history--Sources.
Romagna (Italy)--History--Congresses.
Romagna (Italy)--Politics and government--Sources.
Princeton subject headings:
Papal States--History--Sources--Congresses.
Romagna (Italy)--History--Sources--Congresses.