Columbia subject headings:
Harvard subject headings:
Archivio vaticano
Boyle, Leonard E.
Catholic Church--History.
Europe, Southern--Relations--Scandinavia.
Scandinavia--History.
Scandinavia--Relations--Europe, Southern.
Princeton subject headings:
Church history--Middle Ages, 600-1500.
Europe, Southern--Relations--Scandinavia.
Scandinavia--History.
Scandinavia--Relations--Europe, Southern.