SILICON GERMANIUM THERMOELECTRIC MATERIALS AND MODULE DEVELOPMENT PROGRAM. Topical Report, January 1, 1968--November 1, 1969., report, October 31, 1970; (https://digital.library.unt.edu/ark:/67531/metadc1033140/m1/1/: accessed March 19, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .