Alex,
Those books that you 'found' are classroom textbooks; and they are generally only made available to students who are taking the underlying class.
For these classes, SAP loads data into their training systems that support the classroom curricula, prior to the start of each class.
So, the easy answer is "take the SAP class". If you take the class, SAP will provide you with a new copy of the course material, and once you are in the classroom, you are generally provided with access to their training system, which is consistent with the course material.
SCM200 - Business Processes in Planning (SAP SCM) | SAP Training and Certification Shop
SCM210 - Core Interface (CIF) | SAP Training and Certification Shop
Best Regards,
DB49