1. Agren, Ch.: 1994, New agreement on sulphur,Acid News 4, 10–11.
2. Balcar, V. and Vacek, S.: 1994, ‘Dynamics of Forest Stand Damages in Mountains Regions’, in:State of Mountains Forest of Sudet in Czech Republik, Institute of forest management and hunting, Jiloviště-Strnady, Forest Station Opočno, pp. 51–72.
3. Bergmann, W.: 1986, Farbatlas Ernährungsstörungen bei Kulturpflanzen. Fischer, Jena, pp. 124.
4. Bublinec, E.: 1989, Evaluation of forest health state by the Slovak Academy of Science (in Slovak). Proceedings of a Symposium. Forest Research Institute, Zvolen, 202–203.
5. CEC-UN/ECE: 1993, Forest Condition in Europe. Results of the 1992. CEC-UN/ECE Brussels, Geneva, 1993, p. 37.