1. S. Hawking, “I think the next century will be the century of complexity”, in: San José Mercury News, morning final ed., January 23 (2000).
2. M. Perakh, “Defining complexity”, On Talk Reason, www.talkreason.org/articles/complexity.pdf, August (2004).
3. Toward a quantitative theory of self-generated complexity
4. Complexity as thermodynamic depth