Hammond, J. P.; Slaughter, G. M. & Gurtner, F. B. HETEROGENEITY OF FUSION WELDS DETERMINED BY USE OF $sup 63$Ni-TAGGED FILLER METAL., report, October 31, 1972; (https://digital.library.unt.edu/ark:/67531/metadc1035220/m1/1/: accessed April 25, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .