Dare, W. L. & Delicate, D. T. Mining Methods and Costs: La Sal Mining & Development Co., La Sal Uranium Mine, San Juan County, Utah, report, September 1957; (https://digital.library.unt.edu/ark:/67531/metadc67077/m1/1/: accessed April 25, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .