1. Agency for Toxic Substances and Diseases Registry (2001) Case studies in environmental medicine: Nitrate/nitrite toxicity, US Department of Health and Human Services, Atlanta.
2. Ahmed A.H.H. (1996) Physiological studies on tipburn and nitrate accumulation in lettuce plants, J. Agr. Sci. 21, 3971–3994.
3. Ahmed A.H.H., Khalil M.K., Farrag A.M. (2000) Nitrate accumulation, growth, yield and chemical composition of Rocket (Eruca vesicaria subsp. sativa) plant as affected by NPK fertilization, kinetin and salicylic acid, in: Proceedings of ICEHM 2000, Cairo University, Egypt, pp. 495–508.
4. Andrews M. (1986) The partitioning of nitrate assimilation between root and shoot of higher plants: mini review, Plant Cell Environ. 9, 511–519.
5. Anjana, Umar S., Iqbal M., Abrol Y.P. (2006) Are nitrate concentrations in leafy vegetables within safe limits? Proceedings of the Workshop on Nitrogen in Environment, Industry and Agriculture, New Delhi, India, pp. 81–84.