TY  - RPRT
TI  - Letter Circular 547: preparation and colorimetric properties of a magnesium-oxide reflectance standard (superseding Letter Circular 395)
PY  - 1939
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 547
DO  - 10.6028/NBS.LCIRC.547
ER  -