National Research Council (U.S.). Highway Research Board, National Research Council (U.S.). Highway Research Board. Meeting, & National Research Council (U.S.). Special Committee on International Cooperative Activities. (1972). Soils and bases : characteristics, classification, and planning: 16 reports prepared for the 51st Annual Meeting. Highway Research Board.

National Research Council (U.S.). Highway Research Board, National Research Council (U.S.). Highway Research Board. Meeting, and National Research Council (U.S.). Special Committee on International Cooperative Activities. Soils and Bases : Characteristics, Classification, and Planning: 16 Reports Prepared for the 51st Annual Meeting. Washington: Highway Research Board, 1972.

National Research Council (U.S.). Highway Research Board, et al. Soils and Bases : Characteristics, Classification, and Planning: 16 Reports Prepared for the 51st Annual Meeting. Highway Research Board, 1972.