1. ALLEN, T.F.H. & STARR, T.B. (1982): Hierarchy: Perspectives for ecological complexity.-Chicago, London
2. ASHMORE, M. R. (1988): Methodologies for diagnosis. In: CAPE, J.N. & MATHY, P. (eds.): 203–216
3. ATHARI, S. & KRAMER, H. (1983): The problem of determining growth losses in Norway spruce stands caused by environmental factors. In: ULRICH, B. & PANKRATH, J. (eds.): Effects of accumulating of air pollutants in forest ecosystems.-Dordrecht (…) (Proceedings held at Göttingen, West Germany, May 16–16, 1982): 319–325
4. BENECKE, P. (1987): Die Versauerung bewaldeter Einzugsgebiete. In: Geowissenschaften in unserer Zeit, 5(1): 19–26
5. BLANK, L., ROBERTS, Th. & SKEFHNGTON, R. (1988): New perspectives on forest decline. In: Nature, 336(3): 27–30