S. Maslov, and S. Redner. (2009)cite arxiv:0901.2640
Comment: 3 pages, 1 figure, invited comment for the Journal of Neuroscience.
The arxiv version is microscopically different from the published version.
R. Baeza-Yates, P. Boldi, and C. Castillo. SIGIR '06: Proceedings of the 29th annual international ACM SIGIR conference on Research and development in information retrieval, page 308--315. New York, NY, USA, ACM Press, (2006)