Resource suggestions please: History of Goju Ryu.

Hello,

I'll be grading for my Nidan in the next few months, and I'm required to write an essay on the history of Goju Ryu.

I've collected some resources on-line, from our Dojo handbook, and from some other Nidans and Sandans at our Dojo.

I thought I'd ask here if anyone has any good resources regarding the topic.

I'd appreciate any suggestions.

Thanks!