Columbia subject headings:
Harvard subject headings:
Christianity and other religions
Christianity and other religions--Congresses
Emigration and immigration--Religious aspects
Emigration and immigration--Religious aspects--Congresses.
Missions--Congresses
Muslims--Germany--Congresses.
Muslims--Germany.
Muslims--Non-Islamic countries
Muslims--Non-Islamic countries--Congresses.
Princeton subject headings:
Christianity and other religions--Congresses.
Emigration and immigration--Religious aspects--Congresses.
Muslims--Germany--Congresses.
Muslims--Non-Muslim countries--Congresses.