Science of Volcanoes. (2013). The History Channel website. Retrieved 6:29, May 24, 2013, from http://www.history.com/videos/the-science-of-volcanoes.
Science of Volcanoes. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/videos/the-science-of-volcanoes [Accessed 24 May 2013].
“Science of Volcanoes.” 2013. The History Channel website. May 24 2013, 6:29 http://www.history.com/videos/the-science-of-volcanoes.
“Science of Volcanoes,” The History Channel website, 2013, http://www.history.com/videos/the-science-of-volcanoes [accessed May 24, 2013].
“Science of Volcanoes,” The History Channel website, http://www.history.com/videos/the-science-of-volcanoes (accessed May 24, 2013).
Science of Volcanoes [Internet]. The History Channel website; 2013 [cited 2013 May 24] Available from: http://www.history.com/videos/the-science-of-volcanoes.
Science of Volcanoes, http://www.history.com/videos/the-science-of-volcanoes (last visited May 24, 2013).
Science of Volcanoes. The History Channel website. 2013. Available at: http://www.history.com/videos/the-science-of-volcanoes. Accessed May 24, 2013.