Cita APA (7a ed.)
Duffy, E. (2011). Ten popes who shook the world. Yale University Press.
Cita Chicago Style (17a ed.)
Duffy, Eamon. Ten Popes Who Shook the World. New Haven: Yale University Press, 2011.
Cita MLA (9a ed.)
Duffy, Eamon. Ten Popes Who Shook the World. Yale University Press, 2011.
Precaución: Estas citas no son 100% exactas.