Columbia subject headings:
Harvard subject headings:
Black Sea Coast--Economic conditions--21st century.
Black Sea Coast--Foreign relations.
Black Sea Coast--Politics and government--21st century.
Black Sea Region--Congresses.
Energy policy--Black Sea Coast.
Former Soviet republics--Economic conditions--21st century.
Former Soviet republics--Politics and government--21st century.
International relations
National security--Black Sea Coast.
Power resources--Black Sea Coast.
Russia--Foreign relations.
Turkey--Foreign relations.
Princeton subject headings:
Black Sea Lowland (Ukraine)
Black Sea Lowland (Ukraine)--Politics and government.