1. C. H. Mcdonald, in “Highway Research Record 146” (Highways Research Board), (1966) pp. 1–16.
2. M. R. Piggott, W. Ng, J. D. George and R. T. Woodhams, in “Proceedings of the Association of Asphalt Paving Technologists”, Vol. 46 (1977) p. 495.
3. L. Flynn, Roads Bridges, 12 (1992) 42.
4. W. Moore, “Construction Equipment,” February (Cahners, 1991).
5. T. Kuennen, Roads Bridges January (1992).