Stebbing, L. S. (1939). Thinking to some purpose. Penguin Books.
Chicago-Zitierstil (17. Ausg.)Stebbing, L. Susan. Thinking to Some Purpose. Harmondsworth: Penguin Books, 1939.
MLA-Zitierstil (8. Ausg.)Stebbing, L. Susan. Thinking to Some Purpose. Penguin Books, 1939.
警告：這些引文格式不一定是100％准確.