TY  - RPRT
TI  - Circular of the Bureau of Standards no. 61 2nd edition: specifications and tolerances for weights and measures and weighing and measuring devices
PY  - 1920
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS CIRC 61e2
DO  - 10.6028/NBS.CIRC.61e2
ER  -