Columbia subject headings:
Harvard subject headings:
European Union countries--Foreign relations--Syria.
European Union countries--Foreign relations--Yemen (Republic)
Syria--Foreign relations--European Union countries.
Syria--Politics and government--21st century.
Yemen (Republic)--Foreign relations--European Union countries.
Yemen (Republic)--Politics and government--21st century.
Princeton subject headings:
European Union countries--Foreign Relations--Syria.
European Union countries--Foreign Relations--Yemen (Republic).
Syria--Foreign relations--European Union countries.
Yemen (Republic)--Foreign relations--European Union Countries.