Hurford, J. (1999) Artificially growing a numeral system. In Jadranka Gvozdanovic, editor, Numeral Types and Changes Worldwide , pages 7--41.

Hurford, J. (1999) Artificially growing a numeral system. In Jadranka Gvozdanovic, editor, Numeral Types and Changes Worldwide, pages 7--41.

Beaver, Simulated Evolution of Language and Language Processors, 1997	::	1
Kirby, Natural Language from Artificial Life, 2002	::	67