1. The Acidification of Soils
2. Bolt , G. H. M. G. M. Bruggenwert Soil Chemistry, Der. Soil Sci 5A Elsevier Amsterdam 1976
3. Braekke , F. H. Ion transport and sulphur turnover in peatland in Norwegian SNSF Proj Oslo, Norway 1980
4. Christophersen , N. T. Gulliksen Analysis of hydrologic reservoir models used for water quality simulations Oslo 1981