Changeable message signs

Sonraí bibleagrafaíochta
Údair chorparáideacha:	National Research Council (U.S.). Transportation Research Board, American Association of State Highway and Transportation Officials, United States. Federal Highway Administration
Formáid:	LEABHAR
Teanga:	English
Foilsithe / Cruthaithe:	Washington, D.C. Transportation Research Board, National Research Council 1979.
Ábhair:	Traffic signs and signals.