1. Russell EW, Russell EJ (1961) Soil conditions and plant growth, 9th edn. Longman, London
2. Bowen HJM (1966) Trace elements in biogeochemistry. Academic Press, London
3. Scott AD, Smith SJ (1987) Sources, amounts, and forms of alkali elements in soils. In: Sparks DL (ed) Advances in soil science. Springer, New York, pp 101–147
4. Alloway BJ (2005) Bioavailability of elements in soil. In: Selinus O, Alloway B, Centeno JA, Finkelman RB, Fuge R, Lindh U, Smedley P (eds) Essentials of medical geology–impacts of the natural environment on public health. Elsevier/Academic Press, London, pp 347–372
5. Chellan P, Sadler PJ (2015) The elements of life and medicines. Philos Trans R Soc A 373(2037):20140182