First B-52 shot down over North Vietnam. (2013). The History Channel website. Retrieved 5:04, May 24, 2013, from http://www.history.com/this-day-in-history/first-b-52-shot-down-over-north-vietnam.
First B-52 shot down over North Vietnam. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/first-b-52-shot-down-over-north-vietnam [Accessed 24 May 2013].
“First B-52 shot down over North Vietnam.” 2013. The History Channel website. May 24 2013, 5:04 http://www.history.com/this-day-in-history/first-b-52-shot-down-over-north-vietnam.
“First B-52 shot down over North Vietnam,” The History Channel website, 2013, http://www.history.com/this-day-in-history/first-b-52-shot-down-over-north-vietnam [accessed May 24, 2013].
“First B-52 shot down over North Vietnam,” The History Channel website, http://www.history.com/this-day-in-history/first-b-52-shot-down-over-north-vietnam (accessed May 24, 2013).
First B-52 shot down over North Vietnam [Internet]. The History Channel website; 2013 [cited 2013 May 24] Available from: http://www.history.com/this-day-in-history/first-b-52-shot-down-over-north-vietnam.
First B-52 shot down over North Vietnam, http://www.history.com/this-day-in-history/first-b-52-shot-down-over-north-vietnam (last visited May 24, 2013).
First B-52 shot down over North Vietnam. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/first-b-52-shot-down-over-north-vietnam. Accessed May 24, 2013.