TY  - RPRT
TI  - Letter Circular 662: specifications for the manufacture and installation of four-section and of two-section, knife-edge railway track scales (supersedes NBS Circular C83 and C333)
PY  - 1941
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 662
DO  - 10.6028/NBS.LCIRC.662
ER  -