National Research Council (U.S.). Highway Research Board. (1957). Pavement condition surveys: Suggested criteria. Highway Research Board.
Citação norma ChicagoNational Research Council (U.S.). Highway Research Board. Pavement Condition Surveys: Suggested Criteria. Washington, D.C: Highway Research Board, 1957.
Citação norma MLANational Research Council (U.S.). Highway Research Board. Pavement Condition Surveys: Suggested Criteria. Highway Research Board, 1957.
Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.