In 1961 many nations joined together to create a simplified method of "legalizing" documents for universal recognition.  Members of the conference, referred to as the Hague Convention, adopted a document referred to as an Apostille that would be recognized by all member nations.  Apostilles are basically certifications by your state's Secretary of State that your notary is properly licensed.  Documents sent to member nations, completed with an Apostille at the state level, may be submitted directly to the member nation without further action. It is by this Convention that Russia will accept documents that have been "apostilled" as authentic. 

www.ss.ca.gov/business/notary/notary_authentication.htm