Columbia subject headings:
Europe, Eastern--Foreign relations--European Union countries.
European Union countries--Foreign relations--Europe, Eastern.
European Union countries--Foreign relations--Russia (Federation)
Russia (Federation)--Foreign relations--European Union countries.
Ukraine--Politics and government.
Harvard subject headings:
Europe, Eastern--Foreign relations--European Union countries.
European Union countries--Foreign relations--Europe, Eastern.
European Union countries--Foreign relations--Russia (Federation)
Russia (Federation)--Foreign relations--European Union countries.
Ukraine--Politics and government.
Princeton subject headings:
Crimea (Ukraine)--History--2014-
Europe, Eastern--History--1989-
European Union countries--Foreign relations--Russia (Federation).
European Union countries--Foreign relations--Ukraine.
Russia (Federation)--Foreign relations--European Union countries.
Russia (Federation)--Foreign relations--Ukraine.
Ukraine--Foreign relations--European Union countries.
Ukraine--Foreign relations--Russia (Federation).