Tried to watch the TV series - couldn't stomach it. Did find this book fascinating when it first came out in (I think) 2002 - and there's a new edition around now connected to the Underbelly franchise.
Blurb from the Book:
In the 1920s and '30s in inner Sydney, some of the most terrifying criminals in Australia's history waged war with razor and gun over the spoils of illegal drugs and alcohol, prostitution, gambling and extortion.
The true story of the netherworld of violence and crime that existed in the inner-city ghettoes of East Sydney in the 1920s, and the extraordinary characters that populated it. Gang leaders like Tilly Devine, Kate Leigh and Phil Jeffs made fortunes, whilst their henchmen extorted, bashed and killed with impunity.