Crone, Wendy; Cao, Guoping & Sridhara, Kumar. Assessment of Embrittlement of VHTR Structural Alloys in Impure Helium Environments, report, May 31, 2013; (https://digital.library.unt.edu/ark:/67531/metadc836772/m1/1/: accessed September 21, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .