Haire, M.J. & Schryver, J.C. Establishing Availability Requirements Using Characteristics Factors and Expert Opinion, article, June 18, 2000; (https://digital.library.unt.edu/ark:/67531/metadc706081/m1/1/: accessed January 16, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .