Aerial radiological measuring survey of the area surrounding the Monticello Nuclear Generating Plant, Monticello, Minnesota, August 1970, report, September 1, 1973; (https://digital.library.unt.edu/ark:/67531/metadc1021543/m1/4/: accessed May 20, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .