1. Maurer, J., Libchaber, A., Bergé, P., Dubois, M.: Personal communications
2. Manneville, P., Pomeau, Y.: Phys. Lett.75A, 1 (1979)
3. Arneodo, A., Coullet, P., Tresser, C.: Private communication
4. Iooss, G.: Bifurcation of maps and applications. In: North-Holland Math. Studies 36. Amsterdam, New York: North-Holland 1979
5. Lorenz, E.N.: J. Atmos. Science20, 130 (1963)