Copernicus dies. (2013). The History Channel website. Retrieved 9:22, May 22, 2013, from http://www.history.com/this-day-in-history/copernicus-dies.
Copernicus dies. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/copernicus-dies [Accessed 22 May 2013].
“Copernicus dies.” 2013. The History Channel website. May 22 2013, 9:22 http://www.history.com/this-day-in-history/copernicus-dies.
“Copernicus dies,” The History Channel website, 2013, http://www.history.com/this-day-in-history/copernicus-dies [accessed May 22, 2013].
“Copernicus dies,” The History Channel website, http://www.history.com/this-day-in-history/copernicus-dies (accessed May 22, 2013).
Copernicus dies [Internet]. The History Channel website; 2013 [cited 2013 May 22] Available from: http://www.history.com/this-day-in-history/copernicus-dies.
Copernicus dies, http://www.history.com/this-day-in-history/copernicus-dies (last visited May 22, 2013).
Copernicus dies. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/copernicus-dies. Accessed May 22, 2013.