Conference to Consider the Establishment of Water Quality Standards for the Mississippi River Basin Interstate Waters--State of Iowa (2nd : 1969 : Davenport, Iowa)
Conference to Consider the Establishment of Water Quality Standards for the Missouri River Basin Interstate Waters - State of Iowa (1969 : Council Bluffs, Iowa)
Conference in the Matter of Pollution of Lake Superior and its Tributary Basin in the States of Minnesota, Wisconsin, and Michigan (1970 : Duluth, Minn.)