APA (7th ed.) Zitazioa
Duffy, E. (2011). Ten popes who shook the world. Yale University Press.
Chicago Style (17th ed.) Zitazioa
Duffy, Eamon. Ten Popes Who Shook the World. New Haven: Yale University Press, 2011.
MLA (9th ed.) Zitazioa
Duffy, Eamon. Ten Popes Who Shook the World. Yale University Press, 2011.
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