Hi,
You can check below links:
Courses & Curricula | Supply Chain Management (SCM)
https://training.sap.com/shop/certification/
I would recommend you to go through SAP help library instead of above books as it covers all areas and since you have experience in SAP should not be difficult for you. The only difference is that in books you have some exercises though you can do the same with help library also.
SAP Advanced Planning and Optimization (SAP APO) - SAP Library
If this answers your question follow How to close a discussion and why else raise the concern..
Regards
Rahul