Lyman, Peter; Varian, Hal R. (October 23, 2003). "HOW MUCH INFORMATION 2003?"(PDF). UC Berkeley, School of Information Management and Systems. Archived from the original on December 8, 2017. Retrieved November 25, 2017.
Lyman, Peter; Varian, Hal R. (October 23, 2003). "HOW MUCH INFORMATION 2003?"(PDF). UC Berkeley, School of Information Management and Systems. Archived from the original on December 8, 2017. Retrieved November 25, 2017.