Dix, G. P.; Dobry, T. J., Jr. & Guinn, P. SNAP-III--Thermoelectric Generator Radiological Safety Analysis, report, February 1, 1959; (https://digital.library.unt.edu/ark:/67531/metadc1019914/m1/1/: accessed March 22, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .