TY  - RPRT
TI  - Basic radio propagation predictions for May 1957: three months in advance
PY  - 1957
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS BRPD-CRPL-D 150
DO  - 10.6028/NBS.BRPD-CRPL-D.150
ER  -