Lewis, N. (1973). Thirty days to better English. Dolphin Books.
芝加哥风格引文Lewis, Norman. Thirty Days to Better English. Garden City, N.Y.: Dolphin Books, 1973.
MLA引文Lewis, Norman. Thirty Days to Better English. Dolphin Books, 1973.
警告：这些引文格式不一定是100％准确.