BBC
Bbc News: Soviet Union Timeline
A timeline covering the history of the Soviet Union from 1917 to 1991.
Steven Kreis, PhD
The History Guide: Perestroika Defined (1987)
Perestroika, as defined by Mikhail Gorbachev. This excerpt includes the many definitions and applications of the concept of perestroika when used to describe the internal reforms of the Soviet Union that occurred during the 1980s.