Principles and problems of cooperative. [s.n.].
芝加哥风格引文Principles and Problems of Cooperative. [S.l.]: [s.n.].
MLA引文Principles and Problems of Cooperative. [s.n.].
警告：这些引文格式不一定是100％准确.
APA引文
Principles and problems of cooperative. [s.n.].
芝加哥风格引文Principles and Problems of Cooperative. [S.l.]: [s.n.].
MLA引文Principles and Problems of Cooperative. [s.n.].