United States. Government Accountability Office. Improper Payments: Posthearing Responses on a December 5, 2006, Hearing to Assess the Improper Payments Information Act of 2002, text, February 27, 2007; (https://digital.library.unt.edu/ark:/67531/metadc302281/m1/1/: accessed April 22, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .