Columbia subject headings:
Widows--Europe--History--Congresses.
Widows--Legal status, laws, etc.--Europe--History--Congresses.
Women--Europe--History--Middle Ages, 500-1500--Congresses.
Harvard subject headings:
Widows--Europe--History--Congresses.
Widows--Legal status, laws, etc.--Europe--History--Congresses.
Women--Europe--History--Middle Ages, 500-1500--Congresses.
Princeton subject headings:
Widows--Europe--History.