TY  - RPRT
TI  - Letter Circular 670: alphabetical list of simplified practice recommendations (supersedes Letter Circular 654)
PY  - 1941
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 670r1941
DO  - 10.6028/NBS.LCIRC.670r1941
ER  -