Levine, S.H. & Robinson, G.E. Nineteenth annual progress report of the Pennsylvania State University Breazeale Nuclear Reactor, July 1, 1973 --June 30, 1974, report, June 1, 1974; (https://digital.library.unt.edu/ark:/67531/metadc1023913/m1/1/: accessed November 14, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .