1. 1
    Published 1969
    ...Highway Research Board, National Research Council,...
    Serial
  2. 2
    Published 1988
    ...Transportation Research Board, National Research Council,...
    Journal
  3. 3
    Published 1994
    ...IDEA Program, Transportation Research Board, National Research Council,...
    Book
  4. 4
    Published 1964
    ...Highway Research Board of the Division of Engineering and Industrial Research, National Academy of Sciences, National Research Council,...
    Serial