Gibbons, Anthony B.; Barton, Harlan N.; Kulik, Dolores M. & McDonnell, John R., Jr. Mineral Resources of the Buffalo Hump and Sand Dunes Addition Wilderness Study Areas, Sweetwater County, Wyoming, report, 1990; (https://digital.library.unt.edu/ark:/67531/metadc304441/m1/1/: accessed May 24, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .