Helzer. The Ecology and Management of Prairies in the Central United States. University of Iowa Press.
芝加哥风格引文Helzer. The Ecology and Management of Prairies in the Central United States. University of Iowa Press.
MLA引文Helzer. The Ecology and Management of Prairies in the Central United States. University of Iowa Press.
警告：这些引文格式不一定是100％准确.