Cheetham, N. (1982). Keepers of the keys: A history of the popes from St. Peter to John Paul ll. Charles Scribner's.
芝加哥风格引文Cheetham, Nicholas. Keepers of the Keys: A History of the Popes from St. Peter to John Paul Ll. New York: Charles Scribner's, 1982.
MLA引文Cheetham, Nicholas. Keepers of the Keys: A History of the Popes from St. Peter to John Paul Ll. Charles Scribner's, 1982.
警告：这些引文格式不一定是100％准确.