Columbia subject headings:
Russia (Federation)--Foreign relations--Ukraine.
Ukraine--Foreign relations--Russia (Federation)
Ukraine--History--1991-
Harvard subject headings:
Crimea (Ukraine)--Annexation to Russia (Federation)
Crimea (Ukraine)--Annexation to Russia.
Russia (Federation)--Foreign relations--Ukraine.
Ukraine Conflict, 2014-
Ukraine--Foreign relations--Russia (Federation)
Ukraine--History--Euromaidan Protests, 2013-2014.
Ukraine--Politics and government--1991-
Princeton subject headings:
Crimea (Ukraine)--Annexation to Russia.
Russia (Federation)--Foreign relations--Ukraine.
Ukraine--Foreign relations--Russia (Federation).
Ukraine--History--Euromaidan Protests, 2013-2014.
Ukraine--Politics and government--1991-