Columbia subject headings:
Estonia--History--1940-1991.
Estonia--Politics and government--1940-1991.
Perestroĭka--Estonia.
Harvard subject headings:
Estonia--History--1940-1991.
Estonia--Politics and government--1940-1991.
Perestroĭka--Estonia.
Princeton subject headings:
Estonia--History--1940-1991.
Estonia--Politics and government--1940-1991.
Perestroĭka--Estonia.