World braille usage.

Bibliographic Details
Corporate Authors:	Unesco, Library of Congress. National Library Service for the Blind and Physically Handicapped
Other Authors:	Mackenzie, Clutha Nantes 1895-1966
Format:	Book
Language:	English
Published:	Paris Unesco 1990.
Edition:	[Rev. ed].
Subjects:	Braille. Blind > Printing and writing systems.