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4. Moris, P.O. & Gray, W.J., 1976, “Moisture conditions under roads in the Australian environment”. Australian Road Research Board, Research Report, ARR No. 69.
5. Roy, M. & Johnson, F.D.J., 1979, “M5 Motorway – Blackbrook to Chelston. Report of an Investigation of the Southbound and Northbound Carriageways”, Somerset County Council, Taunton, UK, Report 71/79A, (unpublished).