signal light: 102 phrases in 14 subjects |
Aviation | 1 |
Chemistry | 1 |
Communications | 33 |
Construction | 3 |
Electronics | 5 |
General | 6 |
Lighting other than cinema | 1 |
Natural sciences | 1 |
Nuclear physics | 2 |
Rail transport | 7 |
Road works | 1 |
Telecommunications | 3 |
Transport | 37 |
Vacuum tubes | 1 |