Citation
Severson, R. C. and R. R. Tidball. 1979. “Spatial Variation in Total Element Concentration in Soil Within the Northern Great Plains Coal Region: Geochemical Survey of the Western Energy Regions.” Special Collections, USDA National Agricultural Library. Accessed August 18, 2024, https://www.nal.usda.gov/exhibits/speccoll/items/show/4475.