por Pfeifer, D.W | Scali, M.J., coaut | E.U.A. National Research Council. Transportation Research B-oard.
por Perenchio, W.F | Fraczek, J., coaut.Pfeifer, D.W., coaut | National Research Council. Transportation Research Board (E-.U.A.).
por Landgren, R | Hanson, J. A., coaut.Pfeifer, D. W., coaut.
por Pfeifer, D. W | Hanson, J. A., coaut.