. "History of the Soviet Union" . "Soviet Union" . . . "Soviet history" . "Soviet times" . "History of the Soviet Union" . "history of the country" . "Soviet Era" . . . . . "Soviet past" . . . "history of the Soviet Union" . . "four decades" . "formation of the Soviet Union" . "Soviet developments" . . . "pre-Soviet" . . "history of the USSR" . "era of the Soviet Union" . "history" . "Soviet era" . . "its sixty-nine-year history" . "Soviet Union's history" . "Soviet History" . "socialist revolution" . "Soviet-era" . "69-year-old state" . . . "Soviet period" . . . . . "dissolution of the Soviet Union" . . "entire history" . "Soviet-Era" .