TY  - RPRT
TI  - Letter Circular 1017: standards for checking the calibration of spectrophotometers (200 to 1000 m?)
PY  - 1967
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 1017r1967
DO  - 10.6028/NBS.LCIRC.1017r1967
ER  -