Series of deadly twisters hits U.S. heartland. (2013). The History Channel website. Retrieved 2:45, May 24, 2013, from http://www.history.com/this-day-in-history/series-of-deadly-twisters-hits-us-heartland.
Series of deadly twisters hits U.S. heartland. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/series-of-deadly-twisters-hits-us-heartland [Accessed 24 May 2013].
“Series of deadly twisters hits U.S. heartland.” 2013. The History Channel website. May 24 2013, 2:45 http://www.history.com/this-day-in-history/series-of-deadly-twisters-hits-us-heartland.
“Series of deadly twisters hits U.S. heartland,” The History Channel website, 2013, http://www.history.com/this-day-in-history/series-of-deadly-twisters-hits-us-heartland [accessed May 24, 2013].
“Series of deadly twisters hits U.S. heartland,” The History Channel website, http://www.history.com/this-day-in-history/series-of-deadly-twisters-hits-us-heartland (accessed May 24, 2013).
Series of deadly twisters hits U.S. heartland [Internet]. The History Channel website; 2013 [cited 2013 May 24] Available from: http://www.history.com/this-day-in-history/series-of-deadly-twisters-hits-us-heartland.
Series of deadly twisters hits U.S. heartland, http://www.history.com/this-day-in-history/series-of-deadly-twisters-hits-us-heartland (last visited May 24, 2013).
Series of deadly twisters hits U.S. heartland. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/series-of-deadly-twisters-hits-us-heartland. Accessed May 24, 2013.