Lotka-Volterra-Approach to Cooperation and Competition in Dynamic Systems: Proceedings of the 5th Meeting of UNESCO’s Working Group on System Theory held on the Wartburg, Eisenach (GDR) March 5–9, 1984

Selforganization by Nonlinear Irreversible Processes: Proceedings of the Third International Conference Kühlungsborn, GDR, March 18–22, 1985