George R. Hallberg

• A Progress review of Iowa's agricultural-energy-environmental initiatives
• Changes in the channel area of the Missouri River in Iowa, 1879-1976
• Groundwater monitoring in the Big Spring Basin, 1984-1987
• Illinoian and pre-Illinoian stratigraphy of southeast Iowa and adjacent Illinois
• Pleistocene stratigraphy in east-central Iowa
• Standard procedures for evaluation of Quaternary materials in Iowa