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.
Chicago-viite (17. p.)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.
MLA-viite (9. p.)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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