National Research Council (U.S.). Highway Research Board. (1951). Volcanic ash and laterite soils in highway construction: Presented at the Thirtieth Annual Meeting, 1951. Highway Research Board.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)National Research Council (U.S.). Highway Research Board. Volcanic Ash and Laterite Soils in Highway Construction: Presented at the Thirtieth Annual Meeting, 1951. Washington, D.C: Highway Research Board, 1951.
Trích dẫn kiểu MLA (xuất bản lần thứ 9)National Research Council (U.S.). Highway Research Board. Volcanic Ash and Laterite Soils in Highway Construction: Presented at the Thirtieth Annual Meeting, 1951. Highway Research Board, 1951.
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