Columbia subject headings:
Harvard subject headings:
Perestroĭka--Congresses
Soviet Union--Foreign relations--1985-1991--Congresses.
Soviet Union--Politics and government--1985-1991--Congresses.
Princeton subject headings:
Perestroĭka--Congresses.
Soviet Union--Foreign policy--1985---Congresses.
Soviet Union--Politics and government--1985-1991--Congresses.