A. Guckenheimer and P. Holmes, Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields Springer, 1983.

K. Arrowsmith and M. Place, Differential Systems: Differential Equations , Maps, and Chaotic Behavior Chapman and Hall 14 This effect was in fact anticipated some time ago; see J. Jeener, P. Broakaert , and A. Vlassenbroek, Collective effects in high resolution liquid NMR, Lecture Notes for the 14th Waterloo NMR Summer School, 1992.