1. Wohler’s Associates Inc., 3D Printing and Additive Manufacturing State of the Industry Annual Worldwide Progress Report (Fort Collins, CO: Wohler’s Associates Inc., 2014).
2. S.F. Jacobsen, Hype Cycle for Leaders of Manufacturing Strategies (Ridgefield Park, NJ: Gartner Inc., 2013).
3. “Print me a stradivarius,” The Economist, 10 February 2011.
4. World’s first plant to print jet engine nozzles in mass production, GE Reports, 15 July 2014, www.gereports.com/post/91763815095/worlds-first-plant-to-print-jet-engine-nozzles-in
5. This electron gun builds jet engines, GE Reports, 17 August 2014, www.gereports.com/post/94658699280/this-electron-gun-builds-jet-engines