This? Well basically in the 50's the US Treasury grew dissatisfied with the FBI's 'there is no mafia' lecture, realized there was a mafia, and put together pages of and pages of a list of top mob guy. It's good if you need to find obscure crime figures or if you only have an alias to go off of. It's not much of a 'book', it's built for historians like us. A lot of times you will find individual FBI files on the internet but this is a compilation.
