TY  - RPRT
TI  - Optical radiation measurements : fundamental principles of absolute radiometry and the philosophy of this NBS program (1968 to 1971) /.
AU  - Geist, Jon
PY  - 1972
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS TN 594-1
DO  - 10.6028/NBS.TN.594-1
ER  -