www.en.m.wikipedia.org
www.mrhalligan,wikipacos.com/file/view
www.h-net.org/review/showrev.php?id=488
www.historylearningsite.co.uk/russia
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http://www.historytoday.com/john-etty/russia%E2%80%99s-climate-and-geography
http://en.wikipedia.org/wiki/Timeline_of_Russian_innovation
https://www.marxists.org/glossary/events/w/ww1/russia.htm
www.mrhalligan,wikipacos.com/file/view
www.h-net.org/review/showrev.php?id=488
www.historylearningsite.co.uk/russia
www.marxists.org/ww1/russia
http://www.historytoday.com/john-etty/russia%E2%80%99s-climate-and-geography
http://en.wikipedia.org/wiki/Timeline_of_Russian_innovation
https://www.marxists.org/glossary/events/w/ww1/russia.htm