1. Appelo, C.A.J.: 1982, “Acidification of ground water within quartz-rich sediments of the Netherlands Veluwe area”, Working paper, 12th Annual Symp. Analyt. Chem. Pollutants, Amsterdam.
2. Begheijn, L.Th.: 1980, “Methods of chemical analyses for soils and waters”, Dept. Soil Science and Geology, Agric. Univ., Wageningen, the Netherlands, 100 pp.
3. Likens, G.E., Bormann, F.H., Pierce, R.S., Eaton, J.S., and Johnson, N.M.: 1977, “Biogeochemistry of a forested ecosystem”, Springer Verlag, N.Y., 146 pp.
4. Minderman, G.: 1968, J. Ecol. 56, pp. 355–362.
5. Overrein, L.N., Seip, H.M. and Tollan, A.: 1980, “Acid precipitation, effects on forest and fish”. SNSF project, Ås, Norway, 175 pp.