TY  - RPRT
TI  - Some psycho-physical tests of the conspicuities of emergency vehicle warning lights 
AU  - Howett, Gerald L
PY  - 1979
PB  - National Bureau of Standards
CY  - Gaithersburg, MD
SN  - NBS SP 480-36
DO  - 10.6028/NBS.SP.480-36
ER  -