TY  - RPRT
TI  - Calculation of sunrise and sunset times at ionospheric heights along a great circle path 
AU  - Brady, A H
PY  - 1964
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS TN 209
DO  - 10.6028/NBS.TN.209
ER  -