Gula, R. M. (1982). What are they saying about moral norms? Paulist Press.
芝加哥风格引文Gula, Richard M. What Are They Saying About Moral Norms? New York: Paulist Press, 1982.
MLA引文Gula, Richard M. What Are They Saying About Moral Norms? Paulist Press, 1982.
警告：这些引文格式不一定是100％准确.