Hagel, I. (1976). Alternative energy strategies: Constraints and opportunities. Praeger.
芝加哥风格引文Hagel, III. Alternative Energy Strategies: Constraints and Opportunities. New York: Praeger, 1976.
MLA引文Hagel, III. Alternative Energy Strategies: Constraints and Opportunities. Praeger, 1976.
警告：这些引文格式不一定是100％准确.