Columbia subject headings:
Harvard subject headings:
Families--History.
Families--Religious aspects--Christianity--History--Congresses.
Families--Religious aspects--Judaism--History--Congresses.
Marriage--History.
Marriage--Religious aspects--Christianity--History--Congresses.
Marriage--Religious aspects--Judaism--History--Congresses.
Religion and sociology.
Princeton subject headings:
Families--Europe--Religious aspects--Congresses.
Marriage--Europe--Religious aspects--Congresses.