Co-sign to what MMD wrote. Also check out "The Outfit" by Gus Russo.

Another one, although the fiction to non-fiction ratio may be somewhat higher than normal whistle lol is "Double Cross" by Sam & Chuck Giancana. He also has an entry in "The Mafia Encyclopedia".

All three books describe him as someone that was extremely mean, even for a boss.

"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming

Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.