1. Anderson, R.M. (1936, 10 Oct.) Agricultural History 157–205.
2. Anon., (1972, 19 May) Farmer’s Weekly, 68–69.
3. Anon., (1972, 12 May) Farmer’s Weekly, (Extra) Corn Harvesting.
4. Arnold, R.E. and Jones, M.P. (1963). J. agric. Engng. Res., 8, 178–184.
5. Arnon, I. (1972). Crop Production in Dry Regions. 1, Background and Principles, 2. Systematic treatment of the principle crops. London: Leonard Hill (Books).