Columbia subject headings:
Church history--Middle Ages, 600-1500--Sources.
Councils and synods--History--Sources.
Germany--History--843-918--Sources.
Harvard subject headings:
Carolingians--Sources.
Church history--Middle Ages, 600-1500--Sources.
Councils and synods--Europe--History--Sources.
Europe--Church history--Sources.
Princeton subject headings:
Church history--Middle Ages, 600-1500--Sources.
Germany--Church history--843-1517--Sources.