German submarine sinks Lusitania. (2013). The History Channel website. Retrieved 2:51, May 20, 2013, from http://www.history.com/this-day-in-history/german-submarine-sinks-lusitania.
German submarine sinks Lusitania. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/german-submarine-sinks-lusitania [Accessed 20 May 2013].
“German submarine sinks Lusitania.” 2013. The History Channel website. May 20 2013, 2:51 http://www.history.com/this-day-in-history/german-submarine-sinks-lusitania.
“German submarine sinks Lusitania,” The History Channel website, 2013, http://www.history.com/this-day-in-history/german-submarine-sinks-lusitania [accessed May 20, 2013].
“German submarine sinks Lusitania,” The History Channel website, http://www.history.com/this-day-in-history/german-submarine-sinks-lusitania (accessed May 20, 2013).
German submarine sinks Lusitania [Internet]. The History Channel website; 2013 [cited 2013 May 20] Available from: http://www.history.com/this-day-in-history/german-submarine-sinks-lusitania.
German submarine sinks Lusitania, http://www.history.com/this-day-in-history/german-submarine-sinks-lusitania (last visited May 20, 2013).
German submarine sinks Lusitania. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/german-submarine-sinks-lusitania. Accessed May 20, 2013.