If you are fan of basketball from the sixties and seventies I highly recommend that book : Loose Balls. It's an interview style book and the author talks to everyone he could from the ABA, including all the big names.
The ABA nearly forced a merger in 1970 because a disgruntled employee from the NBA commissioner's office leaked documents listing the order of the draft, which players the teams would draft, and how much money the teams would offer. Of course this was before the draft was held. The ABA threatened to sue (even though they were doing the same thing) and all of a sudden a merger agreement was worked out. It was killed off by the NBA players association who sued the leagues claiming it would create a monopoly. The government stepped in and made a lot of changes to the agreement, including giving the players free agency after one year in the league. Both sides rejected the new agreement and the merger was called off.