The following figures are reproduced with the permission of the named copyright owners:
Figure 9: Johan Hidding.
Figures 11, 41: Wikimedia Commons. Reproduced under the terms of the GNU Free Documentation License.
Figures 15, 16, 17: Wang Sang Koon, Martin Lo, Shane Ross and Jerrold Marsden.
Figure 31: Andrzej Stasiak.
Figure 43: BMW Sauber Formula 1 Team.
Figure 53: Willem Schaap.
Figure 59: Jef Huisman and Franz Weissing, Nature 402 (1999) 407-410.