United States Environmental Protection Agency ; National Effluent Toxicity Assessment Center, Environmental Research Laboratory - Duluth, Office of Water Enforcement and Permits, Office of Water Regulations and Standards, Office of Health and Environmental Assessment - Cincinnati
Conference in the Matter of Pollution of the Interstate Waters of the Colorado River and Its Tributaries in the States of California, Colorado, Utah, Arizona, Nevada, New Mexico, and Wyoming (7th : 1972 : Denver)