ebrary, Inc, Krochalis, J., & Peters, E. (1982). The world of Piers Plowman. University of Pennsylvania Press.
芝加哥风格引文ebrary, Inc, Jeanne Krochalis, 与 Edward Peters. The World of Piers Plowman. Philadelphia: University of Pennsylvania Press, 1982.
MLA引文ebrary, Inc, et al. The World of Piers Plowman. University of Pennsylvania Press, 1982.
警告：这些引文格式不一定是100％准确.