Book on the warlord era in China 1912-1937.......

[Old TImer]

Really slim pickings from what I've been able to find.  One looks interesting regarding the Green Gang in Shanghai.  Amazon wants $50.00 for the e-book. Say what? 
Does anybody have any suggestions on this esoteric chapter?

[ArizonaTank]

Yes, slim pickings indeed.

There are a few US intel background style papers on Archive.org  For example:

https://archive.org/details/DTIC_AD0683470

[Tripoli]

Not a book, but a game on the topic that may help supplement any reading you can find:
https://store.steampowered.com/app/1189100/Rise_Of_The_White_Sun/

[Gusington]

^I had no idea that game even existed. Thanks!

[bobarossa]

^I had no idea that game even existed. Thanks!

https://www.grogheads.com/forums/index.php?topic=27137.msg731556#msg731556

What I find particularly funny is that you were the first person to reply in that thread!

[Gusington]

Eek. Well I never advertised that I had a good memory 

[Tripoli]

Eek. Well I never advertised that I had a good memory 

To complete the "Groghead Hat trick", you now have to buy it, so you can forget you own it.   

[Gusington]

I am afraid to see if I did already...

I didn't