1. Abrahamsen, G., Bjor, K. and Teigen, O.: 1976, ?Field experiments with simulated acid rain in forest ecosystems?. SNSF-Project, Norway FR 4/76 p.15.
2. Abrahamsen, G.: 1980a, ?Acid precipitation, plant nutrients and forest growth?. In Drablos, D. and Tollan, A. (eds.), Proc. Int. Conf. Ecol. Impact Acid Precip., SNSF-Project, Norway 1980, 58.
3. Abrahamsen, G.: 1980b, ?Impact of atmospheric sulphur deposition on forest ecosystems?. In Schriner, D.S., Richmond, C.R. and Lindberg, S.E. (eds.), Atmospheric sulfur deposition. Environmental Impact and Health Effects. Ann Arbor Science Publishers, Inc. Ann Arbor, Michigan, 397.
4. Abrahamsen, G.: 1983, ?Sulphur pollution: Ca, Mg and Al in soil and soil water and possible effects on forest trees?. In Ulrich, B. and Pankrath, J. (eds.), Effects of accumulation of air pollutants in forest ecosystems, 207.
5. Abrahamsen, G.: 1986a, ?Assessment of the long-term effect of acid deposition on leaching from forest soil. A methodical study?. Paper presented at the International Symposium on ?Air Pollution and Stability of Coniferous Forest Ecosystems?, Ostravice/Czechoslovakia, Oct. 1?5, 1985, in press.