Hannon, B & Pleszkun, A R. Energy and labor intensities projected to the year 2010. [For a 40-sector economy], report, September 1, 1978; (https://digital.library.unt.edu/ark:/67531/metadc1210641/m1/18/: accessed July 16, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .