TY  - RPRT
TI  - Focusing the Fresnel Lens Optical Landing System 
AU  - Mullis, W F
AU  - Nimeroff, I
AU  - Walters, E L
PY  - 1975
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS IR 75-644
DO  - 10.6028/NBS.IR.75-644
ER  -