National Research Council (U.S.). Highway Research Board. (1957). Pavement condition surveys: Suggested criteria. Highway Research Board.
Chicago-referens (17:e uppl.)National Research Council (U.S.). Highway Research Board. Pavement Condition Surveys: Suggested Criteria. Washington, D.C: Highway Research Board, 1957.
MLA-referens (9:e uppl.)National Research Council (U.S.). Highway Research Board. Pavement Condition Surveys: Suggested Criteria. Highway Research Board, 1957.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.