1. F. P. Bowden andD. Tabor, “The Friction and Lubrication of Solids”, Vols I and II (Oxford University Press, Oxford, 1954 and 1964).
2. E. MacGurdy, “The Notebooks of Leonardo da Vinci” (Cape, London, 1956).
3. G. Amontons,Mém. Acad. Roy.
A (1699) 275.
4. C. A. Coulomb,Mém. Math. Phys. Acad. Roy. (1785) 161.
5. J. Leslie, “An Experimental Enquiry Into the Nature and Propagation of Heat” (Mawman, London, 1804).