Chaotic demonstrations

Q12a: How can you make a chaotic oscillator?
A12a: Two references are:

1.  T. S. Parker and L. O. Chua, Chaos: a tutorial for engineers, _Proceedings
IEEE_ 75 (1987), pp. 982-1008.

2.  _New Scientist_, June 30, 1990, p. 37.

Q12b: What are laboratory demonstrations of chaos?
A12b: Two references are:

1.  K. Briggs, Simple Experiments in Chaotic Dynamics, _American Journal of
Physics_ 55, 12 (Dec 1987), pp. 1083-1089.

2.  J. L. Snider, Simple Demonstration of Coupled Oscillations, _American
Journal of Physics_ 56, 3 (Mar 1988), p. 200.