1. Soviet Union Yale Public content 1990. 2002-06-01T04:00:00Z. 2011-03-28T18:38:38Z. National Geographic Society (U.S.). Cartographic Division. The Society. English. Public. Soviet Union.
2. Soviet Union : forged during a millenium of expansion, the largest country on earth is an unwieldy conglomeration of a hundred ethnolinguistic groups Yale Public content 1990. 2011-02-23T16:13:03Z. 2015-10-21T15:20:38Z. National Geographic Society (U.S.). Cartographic Division. National Geographic Society. English. Public. Soviet Union.