TY  - RPRT
TI  - Mean electron density variations of the quiet ionosphere 4 
AU  - Fine, LA
AU  - Wright, J W
PY  - 1959
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS TN 40-4
DO  - 10.6028/NBS.TN.40-4
ER  -