TY - GEN AU - F C Breckenridge C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1967-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.MONO.75 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1967 TI - Color of signal lights ::their selection, definition, measurement, production, and use ER -