Webster, F. V., <br/><br/>
Traffic signals / 
By f. v. webster and b. m. cobbe 
 - 111 páginas 
 - Road research technical paper ;  no. 56 .
<br/><br/> A la cabeza de la portada: road research laboratory, ministry of transport 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Transito--Signos y señales--Gran Bretaña
<br/><br/><label>LC Class. No.: </label>HE5615  / W43