Dobzhansky, T. (1962). Genetics and the origin of species. New York, Columbia University Press.
2.
Campbell, B. (1966). Human evolution. London, Heinemann Education Books Ltd.
3.
Tindale, N. & Lindsay, H.A. (1963). The Australian aborigines. London, Angus & Robertson Ltd.
4.
Bowles, J.A. (1969). A comparison of energy expenditure and the diet of hunter-gatherers and primitive agriculturists. Degree dissertation, University of Surrey.
5.
Painter, N.S. & Burkitt, D.P. (1971). Diverticular disease of the colon: a deficiency disease of Western civilization. British Medical Journal, 2, 450.
6.
Mayo, W.J. (1930). Diverticulitis Annals of Surgery, 92, 739.
7.
Parks, T.G. (1968). Post-mortem studies on the colon with special reference to diverticular disease. Proceedings of the Royal Society of Medicine, 61, 932.
8.
Hughes, L.E. (1969). Post-mortem survey of diverticular disease of the colon. Gut, 10, 336.
Hult, L. (1954). The Munkfors investigation. Acta Orthopaedica Scandinavica, Suppi. 16.
15.
Troup, J.D.G. (1968). The function of the lumbar spine. Ph.D. Thesis, London University.
16.
Davis, P.R. (1959). The causation of herniae by weight-lifting. Lancet, 2, 155.
17.
Morris, J.H. , Lucas, D.B. & Bresler , B. (1961). Role of the trunk in stability of the spine. Journal of Bone and joint surgery, 43A, 327.
18.
Davis, P.R. & Troup, J.D.G. (1965). Pressures in the trunk cavities when pulling, pushing and lifting. Ergonomics , 7, 465.
19.
International Labour Office ( 1964). Maximum permissible weight to be carried by one worker . Occupational safety & health series No. 5, Geneva, I.L.O.
20.
Grieve, J.I. (1967). Daily activities of housewives with young children and estimation of energy expenditure. Ergonomics, 10, 25.