@misc{indiciae248d559856b0, title = {Surface water supply of the United States, 1961-65: Part 5. Hudson Bay and upper Mississippi River basins: Volume 2. Upper Mississippi River basin above Keokuk, Iowa}, author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey}, year = {1971}, doi = {10.3133/wsp1914}, url = {https://pubs.usgs.gov/publication/wsp1914}, note = {Source identifier: wsp1914} }