Richards, J. (1979). The popes and the papacy in the early Middle Ages, 476 - 752. Routledge & Kegan Paul.
芝加哥风格引文Richards, Jeffrey. The Popes and the Papacy in the Early Middle Ages, 476 - 752. London [u.a.]: Routledge & Kegan Paul, 1979.
MLA引文Richards, Jeffrey. The Popes and the Papacy in the Early Middle Ages, 476 - 752. Routledge & Kegan Paul, 1979.
警告：这些引文格式不一定是100％准确.