TY  - RPRT
TI  - Basic radio propagation predictions for September 1957: three months in advance
PY  - 1957
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS BRPD-CRPL-D 154
DO  - 10.6028/NBS.BRPD-CRPL-D.154
ER  -