TY  - RPRT
TI  - Letter Circular 171: requirements, construction and operation of apparatus for measurement of the frequencies of distant radio transmitting stations
PY  - 1926
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 171r1926
DO  - 10.6028/NBS.LCIRC.171r1926
ER  -