TY  - RPRT
TI  - Circular of the Bureau of Standards no. 122 2nd edition: sources of elementary radio information
PY  - 1923
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS CIRC 122e2
DO  - 10.6028/NBS.CIRC.122e2
ER  -