Short works
- Non-Uniform Cellular Automata: Evolution in Rule Space and Formation of Complex Structures. 1994. (In Artificial Life IV )
- Quasi-Uniform Computation-Universal cellular automata. 1995. (In Advances in Artificial Life )
- Design, Observation, Surprise! A test of emergence. 1999. (In Emergence )
- Testing for Emergence in Artificial Life. 1999. (In Advances in Artificial Life, ECAL'99 )
- A Self-Replicating Universal Turing Machine: From von Neumann's Dream to New Embryonic Circuits. 2000. (In Artificial Life VII )
- Engineering, Emergent Engineering, and Artificial Life: Unsurprise, Unsurprising Surprise, and Surprising Surprise. 2000. (In Artificial Life VII )
- Interactive Self-Replicating, Self-Incrementing and Self-Decrementing Loops. 2003. (In Artificial Life VIII )