1. Abbott, R.: Complex systems + systems engineering = complex systems engineering. In: Conf. on Systems Engineering Research, California State University, Los Angeles and The Aerospace Corporation. Tech. Rep. (2006)
2. Abbott, R.: Putting complex systems to work. Complexity 13, 30–49 (2007)
3. Aczel, P.: Non-well-founded Sets. Stanford, CSLI (1988)
4. Banzhaf, W.: Self-organizing Systems. Encyclopedia of Physical Science and Technology, pp. 589–598. Academic Press, New York (2002a)
5. Banzhaf, W.: Artificial Chemistries–Towards constructive dynamical systems. Nonlinear Phenom. Complex Syst. 5, 318–324 (2002b)