ebrary, Inc, Meine, C., & Knight, R. L. (1999). The essential Aldo Leopold: Quotations and commentaries. University of Wisconsin Press.
芝加哥风格引文ebrary, Inc, Curt Meine, 与 Richard L. Knight. The Essential Aldo Leopold: Quotations and Commentaries. Madison, WI: University of Wisconsin Press, 1999.
MLA引文ebrary, Inc, et al. The Essential Aldo Leopold: Quotations and Commentaries. University of Wisconsin Press, 1999.
警告：这些引文格式不一定是100％准确.