United States. Government Accountability Office. Smithsonian Institution: Additional Information Should Be Developed and Provided to Filmmakers on the Impact of the Showtime Contract, report, December 15, 2006; (https://digital.library.unt.edu/ark:/67531/metadc298598/m1/3/: accessed May 19, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .