"This study surveyed the folksonomy as a complex network. The result indicates that the network, which is composed of the tags from the folksonomy, displays both properties of small world and scale-free."
{. Barabasi, Z. Dezso, E. Ravasz, {. Yook, and Z. Oltvai. Modeling of Complex Systems: Seventh Granada Lectures, 661, page 1--16. Melville, NY, American Institute of Physics, (2003)