Gunfighter Clay Allison killed. (2013). The History Channel website. Retrieved 2:30, May 20, 2013, from http://www.history.com/this-day-in-history/gunfighter-clay-allison-killed.
Gunfighter Clay Allison killed. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/gunfighter-clay-allison-killed [Accessed 20 May 2013].
“Gunfighter Clay Allison killed.” 2013. The History Channel website. May 20 2013, 2:30 http://www.history.com/this-day-in-history/gunfighter-clay-allison-killed.
“Gunfighter Clay Allison killed,” The History Channel website, 2013, http://www.history.com/this-day-in-history/gunfighter-clay-allison-killed [accessed May 20, 2013].
“Gunfighter Clay Allison killed,” The History Channel website, http://www.history.com/this-day-in-history/gunfighter-clay-allison-killed (accessed May 20, 2013).
Gunfighter Clay Allison killed [Internet]. The History Channel website; 2013 [cited 2013 May 20] Available from: http://www.history.com/this-day-in-history/gunfighter-clay-allison-killed.
Gunfighter Clay Allison killed, http://www.history.com/this-day-in-history/gunfighter-clay-allison-killed (last visited May 20, 2013).
Gunfighter Clay Allison killed. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/gunfighter-clay-allison-killed. Accessed May 20, 2013.