1. Boardmail, J. 1990: Soil erosion on the South Downs: A review. In: Boardman, J., Foster, I.D.L. and Dealing, J.A. (Eds), Soil. Erosion on Agricultural Land, John Wiley & Sons, 87–106.
2. Bos, M.G. 1976: Discharge measurements structures. International Institute for Land Reclamation and Improvement/ILRI, Wageningen, The Netherlands.
3. Dorioz, J.M. and Ferhi, A. 1994: Non-point pollution and management of agricultural areas: Phosphorus and nitrogen transfer in an agricultural watershed. Wat. Res. 28(2), 395–410.
4. European Environment Agency 1995a: European Rivers and Lakes. EEA Environmental Monographs 1, 122 p.
5. European Environment Agency 1995b: European Environment The Dobris Assessment, Stanners, D. and Bourdeau, P. (Eds). EEA, Copenhagen, Denmark, 676 p.