1. Gan, Woon Siong. 1992. Application of chaos to sound propagation in random media. In Acoustical Imaging, vol. 19,99–102,ed. H. Ermert, and H. Harjes. New York: Plenum Press.
2. http://library.thinkquest.org/3120/test/c-his1.htm.
3. Chow, W.H. 2002. Acoustic Fractal Imaging Using Diffraction Tomography. M.Eng. thesis, Nanyang Technological University, chapter 5, p. 112.
4. Gleick, J. 1981. Chaos-Making A New Science, 29. New York: McGraw Hill.
5. Laplante, P., Fractal Mania, Windcrest/McGraw Hill, USA.