1. Improvement of water use efficiency in irrigated agriculture: a review;Boutraa;Journal of Agronomy,2010
2. Bruinsma J 2009 The resource outlook to 2050: by how much do land, water and crop yields need to increase by 2050?
3. Commercial Farmers Group 2009 Priorities for Agricultural and Horticultural Research and Development http://www.commercialfarmers.co.uk