Complexity: metaphors, models, and reality - Cowan, G. A.; Pines, David,; Meltzer, David; Cowan, George A.,; Meltzer, David Elliott; Cowan, George A.,; Meltzer, David Elliott; Cowan, George; Pines, David; Meltzer, David; Cowan, G. A; Meltzer, David (Advanced book classics, 1999)