The most popular example of the a simple folding remains the Rössler system proposed in 1976  :
It is characterized by a first-return map with a differentiable critical point separating the increasing and decreasing branches. The Rössler attractor is observed with parameter values , and .
Rössler called this simple stretched and folded ribbon, the spiral chaos. He already sketch the structure of the attractor with a “paper model” as shown in Fig. 2 .
For other parameter values, a more developed chaos is produced. The first-return map to a Poincaré section has now many monotonic branches (Fig. 3). Rössler named that type of chaos, the “funnel chaos”. Its topology has been investigated by Letellier et al . The spiral chaotic attractor corresponds to a phase coherent attractor while the funnel type is phase incoherent .
 O. E. Rössler, An equation for continuous chaos, Physics Letters A, 57 (5), 397-398, 1976.
 O. E. Rössler, Chaotic behavior in simple reaction system, Zeitscrift für Naturforschung A, 31 (3-4), 259-264, 1976.
 C. Letellier, P. Dutertre & B. Maheu, Unstable periodic orbits and templates of the Rössler system : toward a systematic topological characterization, Chaos, 5 (1), 271-282, 1995.
 J. D. Farmer, J. P. Crutchfield, H. Fröling, N. H. Packard & R. S. Shaw, Power spectra and mixing properties of strange attractors. Annals of the New York Academy of Sciences, 357, 453-472, 1980.