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 the nba and the aba merge?" whose answer is 1976.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when did the nba and the aba merge
Useful Output:

Doc 1: 45 years ago, the American Basketball Association put on its final playoffs before merging with the NBA.
Doc 2: June 17, 1976 -- The NBA announces that it is merging with the American Basketball Association, ending a nine-year struggle between the two
Doc 3: If you aren't familiar, the ABA was founded in 1967 as a rival league to the NBA.  After the 1976 season the NBA did decide to merge with the
Doc 4: Prior to joining Tiffany & Bosco in 2015, Michael A. ; The 1976 NBA-ABA merger was not smooth. Amid the transition, Spirits of St. Louis owners
Doc 5: In 1976 the NBA absorbed four teams from the American Basketball Association (ABA), which disbanded that year. (Read James Naismith's 1929