1. Alonso-Sanz, R., Bull, L.: A very effective density classifier two-dimensional cellular automaton with memory. J. Phys. A 42(48), 485,101 (2009)
2. Bénézit, F.: Distributed average consensus for wireless sensor networks. Ph.D. thesis, EPFL, Lausanne (2009). doi: 10.5075/epfl-thesis-4509
3. Boccara, N., Fukś, H.: Number-conserving cellular automaton rules. Fundam. Inform. 52(1–3), 1–13 (2002)
4. Busic, A., Fatès, N., Mairesse, J., Marcovici, I.: Density classification on infinite lattices and trees (2011). ArXiv: 1111.4582 . Short version to appear in the proceedings of LATIN 2012, LNCS series, vol. 7256
5. Capcarrere, M.S., Sipper, M., Tomassini, M.: Two-state, r=1 cellular automaton that classifies density. Phys. Rev. Lett. 77(24), 4969–4971 (1996)