Hudson, W. D. (1973). The is-ought question: A collection of papers on the central problem in moral philosophy (Repr.). Macmillan.
芝加哥风格引文Hudson, W. D. The Is-ought Question: A Collection of Papers on the Central Problem in Moral Philosophy. Repr. London [u.a.]: Macmillan, 1973.
MLA引文Hudson, W. D. The Is-ought Question: A Collection of Papers on the Central Problem in Moral Philosophy. Repr. Macmillan, 1973.
警告：这些引文格式不一定是100％准确.