United States. Government Accountability Office. DOD Financial Management: Weaknesses in Controls over the Use of Public Funds and Related Improper Payments, text, September 22, 2011; (https://digital.library.unt.edu/ark:/67531/metadc300121/m1/1/: accessed February 16, 2020), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .