You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "when did they start putting barcodes on products?" whose answer is July 1972,.
Each document should contain about 30 words, and these documents should contain useful information.

Query: first use of barcodes in retail
Useful Output:

Doc 1: On June 26, 1974, a man named Clyde Dawson asked the cashier at a Marsh store in Troy, Ohio to scan a pack of Wrigley's Juicy Fruit chewing gum with a barcode
Doc 2: It wasn't until April 3rd 1973 that the UPC (Universal Product Code) barcode was adopted as a standard for use in retail stores in the United
Doc 3: Answer: On June 26, 1974, the initial commercial product scanned and sold was a 10-pack of Wrigley's Juicy Fruit gum at Marsh Supermarket in
Doc 4: On March 30, 1973, independent scientists from MIT selected the winning UPC that would be featured on all products sold in supermarkets: Lauer's
Doc 5: Following those years, RCA and IBM vied for barcode dominance until 1974, when the first barcode sale was completed in Troy, Ohio at 8:01 AM