1. WholersT, CaffreyT. Wholers Report 2013: Additive Manufacturing and 3D Printing State of the Industry. Fort Collins, CO: Wholers Associates, Inc., 2013.
2. US Food and Drug Adminstration. Chapter I subchapter B part 175, Indirect Food Additives: Adhesives and Components of Coatings. In Code of Federal Regulations, Title 21 Food and Drugs, Office of the Federal Register, 2015.