Cita APA (7a ed.)

Cheetham, N. (1982). Keepers of the keys: A history of the popes from St. Peter to John Paul ll. Charles Scribner's.

Cita Chicago Style (17a ed.)

Cheetham, Nicholas. Keepers of the Keys: A History of the Popes from St. Peter to John Paul Ll. New York: Charles Scribner's, 1982.

Cita MLA (9a ed.)

Cheetham, Nicholas. Keepers of the Keys: A History of the Popes from St. Peter to John Paul Ll. Charles Scribner's, 1982.