Cheetham, N. Keepers of the keys: A history of the Popes from St. Peter to John Paul II.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCheetham, Nicolas. Keepers of the Keys: A History of the Popes from St. Peter to John Paul II.
एमएलए (8वां संस्करण) प्रशस्ति पत्रCheetham, Nicolas. Keepers of the Keys: A History of the Popes from St. Peter to John Paul II.
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