Columbia subject headings:
Harvard subject headings:
Bulgaria--Foreign relations--European Union countries--Periodicals.
European Union countries--Economic integration--Periodicals.
European Union countries--Foreign relations--Bulgaria--Periodicals.
European Union--Bulgaria--Periodicals.
Princeton subject headings:
Bulgaria--Foreign relations--European Union countries--Periodicals.
European Union countries--Economic integration--Periodicals.
European Union countries--Foreign relations--Bulgaria--Periodicals.
European Union--Bulgaria--Periodicals.
Periodicals.