TY  - RPRT
TI  - Tables of median hourly values of the cosine of the solar zenith angle (x) for thirty-five locations. 
AU  - McDuffie, R E
PY  - 1959
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS TN 5
DO  - 10.6028/NBS.TN.5
ER  -