1. Varian HR Lyman P How much information. University of California at Berkeley, School of Information Management & Systems (SIMS) 2003
2. Gantz JF 2007 http://www.emc.com/collateral/analyst-reports/expanding-digital-idc-white-paper.pdf.
3. When will computer hardware match the human brain;Moravec;J Evol Technol,1998
4. Models of object recognition;Riesenhuber;Nature Neurosci,2000