Columbia subject headings:
Christians--Syria--History--Congresses.
Christians--Turkey--History--Congresses.
Harvard subject headings:
Christianity and other religions--Syria--Islam--Congresses.
Christianity and other religions--Turkey--Islam--Congresses.
Christians--Syria--History--Congresses.
Christians--Turkey--History--Congresses.
Minorities--Syria--History--Congresses.
Minorities--Turkey--History--Congresses.
Princeton subject headings:
Christianity and other religions--Syria--Islam--Congresses.
Christianity and other religions--Turkey--Islam--Congresses.
Christians--Syria--History--Congresses.
Christians--Turkey--History--Congresses.
Minorities--Syria--History--Congresses.
Minorities--Turkey--History--Congresses.