Ruhl, J. F. (1997). Nitrate and pesticides in surficial aquifers and trophic state and phosphorus sources for selected lakes, eastern Otter Tail County, west-central Minnesota, 1993-96. U.S. Geological Survey.
Chicago Style (17th ed.) CitationRuhl, J. F. Nitrate and Pesticides in Surficial Aquifers and Trophic State and Phosphorus Sources for Selected Lakes, Eastern Otter Tail County, West-central Minnesota, 1993-96. Mounds View, Minnesota: U.S. Geological Survey, 1997.
MLA (9th ed.) CitationRuhl, J. F. Nitrate and Pesticides in Surficial Aquifers and Trophic State and Phosphorus Sources for Selected Lakes, Eastern Otter Tail County, West-central Minnesota, 1993-96. U.S. Geological Survey, 1997.
Warning: These citations may not always be 100% accurate.