1. Bell, C.: Getting a 3D printer. Maintaining and troubleshooting your 3D printer, pp. 53–84. Apress, New York (2014)
2. American National Standard: Accessible and usable buildings and facilities. Standard and Commentary. ICC/ANSI A117.1-2003. P151-163 (2003)
3. U.S. Access Board: ABA and ADA accessibility guidelines. http://www.access-board.gov/ada-aba/guide.htm (2004)
4. National Library Service for the Blind and Physically Handicapped, Library of Congress. Specification 800: Braille Books and Pamphlets
5. www.loc.gov/nls/specs/800_march5_2008.pdf . Available in March 2016