Columbia subject headings:
Church history--Middle Ages, 600-1500--Congresses.
Communication--Religious aspects--Christianity--History of doctrines--Middle Ages, 600-1500--Congresses.
Harvard subject headings:
Church history--Middle Ages, 600-1500--Congresses.
Communication--Religious aspects--Christianity--History--Congresses.
Princeton subject headings:
Church history--Middle Ages, 600-1500--Congresses.
Communication--Religious aspects--Christianity--History--Congresses.