1. Abramitzky R. Braggion , F. Malthusian and Neo-Malthusian Theories http://web.stanford.edu/~ranabr/Malthusian%20and%20Neo%20Malthusian1%20for%20webpage%20040731.pdf
2. Land surface zoning for groundwater protection;Adams;J. Inst Water and Env Man.,1992
3. ADAS 2007 Nitrates in water - the current status in England (2006) http://archive.DEFRA.gov.uk/environment/quality/water/waterquality/diffuse/nitrate/documents/consultation-supportdocs/d1-nitrateswater.pdf
4. Agnew , C. Anderson , E. 1992 Water Resources and the Arid Realm Routledge London 329
5. AIC 2015 UK Fertiliser Consumption Trends & Statistic https://www.agindustries.diazorg.uk/sectors/fertiliser/uk-fertiliser-consumption-trends-and-statistics/