How to prepare for PSM II

HI All,

I have cleared my PSM I certification by self-study. Thanks to all the suggestion provided. Now, I am planning to go for PSM II.
It would be great, if I could get some guidelines on references I need to go through and what to expect in the exam and tips for preparation.
Since, the training cost as well as exam fee both are costly. I am planning to go for self study and use my prior scrum experience.
Please suggest.

Thanks and Regards,
Krishna