The eruption of Nevado del Ruiz. (2013). The History Channel website. Retrieved 8:49, May 23, 2013, from http://www.history.com/this-day-in-history/the-eruption-of-nevado-del-ruiz.
The eruption of Nevado del Ruiz. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/the-eruption-of-nevado-del-ruiz [Accessed 23 May 2013].
“The eruption of Nevado del Ruiz.” 2013. The History Channel website. May 23 2013, 8:49 http://www.history.com/this-day-in-history/the-eruption-of-nevado-del-ruiz.
“The eruption of Nevado del Ruiz,” The History Channel website, 2013, http://www.history.com/this-day-in-history/the-eruption-of-nevado-del-ruiz [accessed May 23, 2013].
“The eruption of Nevado del Ruiz,” The History Channel website, http://www.history.com/this-day-in-history/the-eruption-of-nevado-del-ruiz (accessed May 23, 2013).
The eruption of Nevado del Ruiz [Internet]. The History Channel website; 2013 [cited 2013 May 23] Available from: http://www.history.com/this-day-in-history/the-eruption-of-nevado-del-ruiz.
The eruption of Nevado del Ruiz, http://www.history.com/this-day-in-history/the-eruption-of-nevado-del-ruiz (last visited May 23, 2013).
The eruption of Nevado del Ruiz. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/the-eruption-of-nevado-del-ruiz. Accessed May 23, 2013.