Interleaved 2 of 5 specifications. Plessey Code specifications. Y ou can order books about bar code on-line here. The magazine list will lead you to web pages of leading magazines in the bar code and automatic identification industry. Many of these magazines are free to people in the United States.
Several magazines have European issues and Asian issues that are free there.
A list of magazines about bar code. A list of books about bar code. A list of annual trade shows and their links.