Butler. The Tallgrass Prairie Center Guide to Seed and Seedling Identification in the Upper Midwest. University of Iowa Press.
芝加哥风格引文Butler. The Tallgrass Prairie Center Guide to Seed and Seedling Identification in the Upper Midwest. University of Iowa Press.
MLA引文Butler. The Tallgrass Prairie Center Guide to Seed and Seedling Identification in the Upper Midwest. University of Iowa Press.
警告：这些引文格式不一定是100％准确.