Eckholm, E. P. (1978). Disappearing species: The social challenge. Worldwatch Institute.
芝加哥风格引文Eckholm, Erik P. Disappearing Species: The Social Challenge. [Washington]: Worldwatch Institute, 1978.
MLA引文Eckholm, Erik P. Disappearing Species: The Social Challenge. Worldwatch Institute, 1978.
警告：这些引文格式不一定是100％准确.