Cover, T. M. and Hart, P. E. (1967). Nearest neighbour pattern classification. Institute of Electrical and Electronics Engineers Transactions on Information Theory, 13:21--27.

Ferrer-i-Cancho, R. and Sole, R. V. (2003). Least effort and the origins of scaling in human language. Proceedings of the National Academy of Sciences, 100(3):788--791.

Gardenfors, P. (2000). Conceptual Spaces. Bradford Books, MIT Press.

Gunther, R., Levitin, L., Schapiro, B., and Wagner, P. (1996). Zipf's law and the effect of ranking on probability distributions. International Journal of Theoretical Physics, 35(2):395--417.

Kirby, S. (2002). Learning, bottlenecks and the evolution of recursive syntax. In Briscoe, T., editor, Linguistic Evolution through Language Acquisition: Formal and Computational Models. Cambridge University Press.

Li, W. (1992). Random texts exhibit Zipf's law like word frequency distributions. IEEE Transactions on Information Theory, 38(6):1842--1845.

Mandelbrot, B. B. (1953). An information theory of the statistical structure of language. In Jackson, W., editor, Communication Theory, pages 503--512, New York. Academic Press.

Miller, G. A. (1957). Some effects of intermittent silence. American Journal of Psychology, 70:311--314.

Rosch, E. (1978). Principles of categorization. In Rosch, E. and Lloyd, B. B., editors, Cognition and Categorization. Lawrence Erlbaum Ass.

Siskind, J. M. (1996). A computational study of crosssituational techniques for learning word-to-meaning mappings. Cognition, 61:39--91.

Smith, A. D. M. (2003). Intelligent meaning creation in a clumpy world helps communication. Artificial Life, 9(2):559--574.

Smith, K. (forthcoming). The evolution of vocabulary. Journal of Theoretical Biology.

Steels, L. (1996). Perceptually grounded meaning creation. In Tokoro, M., editor, Proceedings of the International Conference on Multi-Agent Systems, Menlo Park Ca. AAAI Press.

Steels, L., Kaplan, F., McIntyre, A., and Van Looveren, J. (2002). Crucial factors in the origins of word-meaning. In Wray, A., editor, The Transition to Language, Oxford, UK. Oxford University Press.

Tullo, C. and Hurford, J. R. (2003). Modelling Zipfian distributions in language. In Kirby, S., editor, Language Evolution and Computation, Proceedings of the workshop at ESSLLI.

Vogt, P. (2000). Bootstrapping grounded symbols by minimal autonomous robots. Evolution of Communication, 4(1):89--118.

Vogt, P. (2003a). Grounded lexicon formation without explicit meaning transfer: who's talking to who? In Banzhaf, W., Christaller, T., Dittrich, P., Kim, J. T., and Ziegler, J., editors, Advances in Artificial Life Proceedings of the 7th European Conference on Artificial Life (ECAL). Springer Verlag Berlin, Heidelberg.

Vogt, P. (2003b). "THSim v3.2: The Talking Heads simulation tool". In Banzhaf, W., Christaller, T., Dittrich, P., Kim, J. T., and Ziegler, J., editors, Advances in Artificial Life Proceedings of the 7th European Conference on Artificial Life (ECAL). Springer Verlag Berlin, Heidelberg.

Vogt, P. (2004). Generalisation as a bias toward the emergence of Zipf's law. In Proceedings of Evolang 5.

Vogt, P. and Smith, A. D. M. (2004). Quantifying lexicon acquisition under uncertainty. In Lenaerts, T., Nowe, A., and Steenhout, K., editors, Proceedings of Benelearn 2004.

Zipf, G. K. (1949). Human Behaviour and the Principle of Least Effort: An Introduction to Human Ecology. Addison-Wesley, Cambridge, MA.