Boris Godunov was a Russian statesman who was chief adviser to Tsar Fyodor I and was himself elected tsar after the extinction of the Rurik dynasty.
Boris Godunov. (2013). The Biography Channel website. Retrieved 12:52, May 19, 2013, from http://www.biography.com/people/boris-godunov-38809.
Boris Godunov. [Internet]. 2013. The Biography Channel website. Available from: http://www.biography.com/people/boris-godunov-38809 [Accessed 19 May 2013].
"Boris Godunov." 2013. The Biography Channel website. May 19 2013, 12:52 http://www.biography.com/people/boris-godunov-38809.
"Boris Godunov," The Biography Channel website, 2013, http://www.biography.com/people/boris-godunov-38809 [accessed May 19, 2013].
"Boris Godunov," The Biography Channel website, http://www.biography.com/people/boris-godunov-38809 (accessed May 19, 2013).
Boris Godunov [Internet]. The Biography Channel website; 2013 [cited 2013 May 19] Available from: http://www.biography.com/people/boris-godunov-38809.
Boris Godunov, http://www.biography.com/people/boris-godunov-38809 (last visited May 19, 2013).
Boris Godunov. The Biography Channel website. 2013. Available at: http://www.biography.com/people/boris-godunov-38809. Accessed May 19, 2013.