(1973). Specification for the construction of road traffic signs and internally illuminated bollards. London: British Standards Institution.
Παραπομπή Chicago StyleSpecification for the Construction of Road Traffic Signs and Internally Illuminated Bollards. London: British Standards Institution, 1973.
Παραπομπή MLASpecification for the Construction of Road Traffic Signs and Internally Illuminated Bollards. London: British Standards Institution, 1973.
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