1. Note: Most references by A. Wuensche are available online at http://www.uncomp.ac.uk/wuensche/publications.html
2. Ashby WR (1956) An introduction to cybernetics. Chapman & Hall, London
3. Conway JH (1982) What is life? In: Berlekamp E, Conway JH, Guy R (eds) Winning ways for your mathematical plays, chapter 25, vol Vol. 2. Academic Press, New York
4. Cook M (2004) Universality in elementary cellular automata. Complex Syst 15:1–40
5. Domain C, Gutowitz H (1997) The topological skeleton of cellular automata dynamics. Pysica D 103(1–4):155–168