Ca. Kruelle et al., NONINTEGRABLE STADIUM BILLIARD SEEN AS MIRROR CABINET, Zeitschrift fur Naturforschung. A, A journal of physical sciences, 48(10), 1993, pp. 1039-1040
The Bunimovich stadium billiard is treated as a mirror cabinet seen fr
om inside. The resulting system of virtual images of the mirror walls
reveals a fractional structure which corresponds to the chaotic trajec
tories of light rays or billiard balls inside the stadium.