TY  - RPRT
TI  - Letter Circular 674: railway track scale testing service of the National Bureau of Standards fiscal year 1941 (July 1, 1940 to June 30, 1941)
PY  - 1941
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 674
DO  - 10.6028/NBS.LCIRC.674
ER  -