Carl Sandburg. (2013). The Biography Channel website. Retrieved 11:58, Jun 19, 2013, from http://www.biography.com/people/carl-sandburg-9470854.
Carl Sandburg. [Internet]. 2013. The Biography Channel website. Available from: http://www.biography.com/people/carl-sandburg-9470854 [Accessed 19 Jun 2013].
"Carl Sandburg." 2013. The Biography Channel website. Jun 19 2013, 11:58 http://www.biography.com/people/carl-sandburg-9470854.
"Carl Sandburg," The Biography Channel website, 2013, http://www.biography.com/people/carl-sandburg-9470854 [accessed Jun 19, 2013].
"Carl Sandburg," The Biography Channel website, http://www.biography.com/people/carl-sandburg-9470854 (accessed Jun 19, 2013).
Carl Sandburg [Internet]. The Biography Channel website; 2013 [cited 2013 Jun 19] Available from: http://www.biography.com/people/carl-sandburg-9470854.
Carl Sandburg, http://www.biography.com/people/carl-sandburg-9470854 (last visited Jun 19, 2013).
Carl Sandburg. The Biography Channel website. 2013. Available at: http://www.biography.com/people/carl-sandburg-9470854. Accessed Jun 19, 2013.