Clement VII was the first antipope (1378–1394) of the Western (Great) Schism that troubled the Roman Catholic church for 40 years.
Antipope Clement VII. (2013). The Biography Channel website. Retrieved 12:27, May 19, 2013, from http://www.biography.com/people/antipope-clement-vii-39125.
Antipope Clement VII. [Internet]. 2013. The Biography Channel website. Available from: http://www.biography.com/people/antipope-clement-vii-39125 [Accessed 19 May 2013].
"Antipope Clement VII." 2013. The Biography Channel website. May 19 2013, 12:27 http://www.biography.com/people/antipope-clement-vii-39125.
"Antipope Clement VII," The Biography Channel website, 2013, http://www.biography.com/people/antipope-clement-vii-39125 [accessed May 19, 2013].
"Antipope Clement VII," The Biography Channel website, http://www.biography.com/people/antipope-clement-vii-39125 (accessed May 19, 2013).
Antipope Clement VII [Internet]. The Biography Channel website; 2013 [cited 2013 May 19] Available from: http://www.biography.com/people/antipope-clement-vii-39125.
Antipope Clement VII, http://www.biography.com/people/antipope-clement-vii-39125 (last visited May 19, 2013).
Antipope Clement VII. The Biography Channel website. 2013. Available at: http://www.biography.com/people/antipope-clement-vii-39125. Accessed May 19, 2013.