Mount St. Helens erupts. (2013). The History Channel website. Retrieved 6:19, May 22, 2013, from http://www.history.com/this-day-in-history/mount-st-helens-eruption.
Mount St. Helens erupts. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/mount-st-helens-eruption [Accessed 22 May 2013].
“Mount St. Helens erupts.” 2013. The History Channel website. May 22 2013, 6:19 http://www.history.com/this-day-in-history/mount-st-helens-eruption.
“Mount St. Helens erupts,” The History Channel website, 2013, http://www.history.com/this-day-in-history/mount-st-helens-eruption [accessed May 22, 2013].
“Mount St. Helens erupts,” The History Channel website, http://www.history.com/this-day-in-history/mount-st-helens-eruption (accessed May 22, 2013).
Mount St. Helens erupts [Internet]. The History Channel website; 2013 [cited 2013 May 22] Available from: http://www.history.com/this-day-in-history/mount-st-helens-eruption.
Mount St. Helens erupts, http://www.history.com/this-day-in-history/mount-st-helens-eruption (last visited May 22, 2013).
Mount St. Helens erupts. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/mount-st-helens-eruption. Accessed May 22, 2013.