Barber, M. (2003). the two cities: Medieval europe 1050-1320 (Second edition.). Routledge.
芝加哥风格引文Barber, Malcolm. The Two Cities: Medieval Europe 1050-1320. Second edition. London: Routledge, 2003.
MLA引文Barber, Malcolm. The Two Cities: Medieval Europe 1050-1320. Second edition. Routledge, 2003.
警告：这些引文格式不一定是100％准确.