1. Bjork, S., 1988. Redevelopment of Lake Ecosystems-A Case-Study Approach, AMBIO Vol. 17 NO.2: 90–98.
2. Ripl, W., Pokorny J., Eiseltova M. and Ridgil S., 1994. An holistic approach to the structure and function of wetlands, and their degradation. In: M. Eiseltova (Ed.), Restoration of Lake Ecosystems, an Holistic Approach. A Training handbook, pp. 16–35.
3. Energy and alternatives for fertilizer and pesticide use;Helsel,1992
4. Munck, L., 1992. The contribution of barley to agriculture today and in the future. Barley Genetics VI, volume II, Barley Research reviews 1986–91 Session and Workshop Summaries. Proceedings of the Sixth International Barley Genetics Symposium, July 22–27 1991, Helsingborg, Sweden. Helsingborg, The Organizing Committee of the Nordic Countries, Sixth International Genetics Symposium pp. 1099–1109.
5. Srivastava, A.K., Goering, C.E., Rohrbach, R.P., 1993. Engineering principles of agricultural machines. In: P. De Vore-Hansen (Ed.), ASAE Textbook Number 6. Books and Journals, American Society of Agricultural Engineers, St. Josephs, Michigan,p. 601.