Columbia subject headings:
Harvard subject headings:
Conversion--Christianity--Congresses.
Missions--Congresses
Scandinavia--Church history--Congresses.
Scandinavia--Church history--Middle Ages, 600-1500--Congresses.
Princeton subject headings:
Christianity--Scandinavia--Middle Ages, 600-1500.
Scandinavia--Church history--Middle Ages, 600-1500.