1. Aber, J. D., Nadelhoffer, K. J, Steudler, P. and Melillo, J. M. (1989) Nitrogen saturation in northern forest systems. Bioscience, 39, 378 - 386.
2. Abrehams, P. W., Tranter, M., Davies, T. D. and Blackwood (1989) Geochemical studies in a remote Scottish upland catchment: II Streamwater chemistry during snow-melt. Water, Air and Soil Pollution, 43, 231 - 248.
3. Adamson, J. K., Scott, W. A. and Rowland, A. P. (1998) The dynamics of dissolved nitrogen in a blanket peat dominated catchment. Environmental Pollution, 99, 69 - 77
4. Allott, T. E. H., Curtis., C. J., Hall. J., Harriman, R. and Battarbee, R. W. (1995) The impact of nitrogen deposition on upland surface waters in Great Britain: A regional assessment of nitrate leaching. Water, Air and Soil Pollution, 85, 297 - 302.
5. Anderson, H. A., Stewart, M., Miller, J. D. and Hepburn, A. (1991) Organic nitrogen in soils and associated surface waters, in Advances in soil organic matter research: The impact of agriculture and the environment, (ed W. S. Wilson ), The Royal Society of Chemistry, Cambridge, pp. 97 - 106.