TY  - RPRT
TI  - Glass limit standards deposited at NBS for railway, highway and airways traffic signal colors : history, permanence and colorimetric properties
AU  - Haupt, Geraldine W
PY  - 1971
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS TN 564
DO  - 10.6028/NBS.TN.564
ER  -