"March 31, 1995." "A cooperative project of USDA-Agricultural Research Service, USDA-Cooperative State Research Education and Extension Service, USDA-Natural Resource Conservation Service, Iowa Agricultural Experiment Station, Iowa Cooperative Extension Service, United States Geological Survey, U.S. Environmental Protection Agency." Includes bibliographical references (leaf 28-37).
This resource is supported by the Institute of Museum and Library Services under the provisions of the Library Services and Technology Act as administered by State Library of Iowa.