G.E. Moore, "Cramming More Components onto Integrated Circuits," Electronics, 38:8 (April 19, 1965), available at http://www.intel.com/research/silicon/moorespaper.pdf.
The Revolution in Information Technology. Remarks by Chairman Alan Greenspan before the Boston College Conference on the New Economy. Boston, Massachusetts, March 6, 2000.
Commerce Department Study, The Emerging Digital Economy II. U.S. Government Publication.
Data from the U.S. Census Bureau report. See http://www.census.gov/mrts/www/current.html.