United States. Government Accountability Office. Value-Added Taxes: Lessons Learned from Other Countries on Compliance Risks, Administrative Costs, Compliance Burden, and Transition, report, April 4, 2008; (https://digital.library.unt.edu/ark:/67531/metadc301986/m1/1/: accessed October 16, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .