Harrison dies of pneumonia. (2013). The History Channel website. Retrieved 2:38, May 23, 2013, from http://www.history.com/this-day-in-history/harrison-dies-of-pneumonia.
Harrison dies of pneumonia. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/harrison-dies-of-pneumonia [Accessed 23 May 2013].
“Harrison dies of pneumonia.” 2013. The History Channel website. May 23 2013, 2:38 http://www.history.com/this-day-in-history/harrison-dies-of-pneumonia.
“Harrison dies of pneumonia,” The History Channel website, 2013, http://www.history.com/this-day-in-history/harrison-dies-of-pneumonia [accessed May 23, 2013].
“Harrison dies of pneumonia,” The History Channel website, http://www.history.com/this-day-in-history/harrison-dies-of-pneumonia (accessed May 23, 2013).
Harrison dies of pneumonia [Internet]. The History Channel website; 2013 [cited 2013 May 23] Available from: http://www.history.com/this-day-in-history/harrison-dies-of-pneumonia.
Harrison dies of pneumonia, http://www.history.com/this-day-in-history/harrison-dies-of-pneumonia (last visited May 23, 2013).
Harrison dies of pneumonia. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/harrison-dies-of-pneumonia. Accessed May 23, 2013.