Columbia subject headings:
Harvard subject headings:
Church history--19th century
Church history--20th century
Missions to Muslims--Syria--History--19th century.
Missions to Muslims--Syria--History--20th century.
Missions--Syria--History--19th century.
Missions--Syria--History--20th century.
Princeton subject headings:
Christianity--Syria--History--19th century.
Christianity--Syria--History--20th century.
Missions to Muslims--Syria--History--19th century.
Missions to Muslims--Syria--History--20th century.
Missions--Syria--History--19th century.
Missions--Syria--History--20th century.