Williams, F. (1935). The sky's the limit: Plain words on plane profits. London: Labour.
芝加哥风格引文Williams, Francis. The Sky's the Limit: Plain Words on Plane Profits. London: Labour, 1935.
MLA引文Williams, Francis. The Sky's the Limit: Plain Words on Plane Profits. London: Labour, 1935.
警告：这些引文格式不一定是100％准确.