Pope Pius VIII

(2004). Cardinal Pietro Ottoboni (1667–1740) and the Vatican tomb of Pope Alexander VIII. Diane Publishing. ISBN 978-0-87169-252-8. Reardon, 2004, p. 218

cardinals elect a Pope. BBC. 2013-02-21 [2017-10-30]. （原始内容存档于2017-12-14） （英语）.  Cardinal Siri: Was he elected Pope Gregory XVII after Pius XII?. Novus Ordo

Papacy: An Encyclopedia. New York: Routledge, 2002. Loughlin, James. "Pope Gregory VIII." The Catholic Encyclopedia. Vol. 6. New York: Robert Appleton Company

(Boston: Houghton Mifflin Company). Kertzer, David I. The Pope and Mussolini: The Secret History of Pius XI and the Rise of Fascism in Europe. Oxford University

Encyclopædia Britannica. Pius VIII. Encyclopædia Britannica. [2017-05-04]. （原始内容存档于2016-03-24） （英语）.  Philip Bump. How Long the Pope Vote Might Last, According