What kind of books do you mean?

First of all, from the perspective of piano grading, the China Conservatory of Music and the Chinese Musicians Association are one grading institution, so the three grading exams you mentioned above are actually just two.

A passing certificate will be issued for both examinations.

There is a difference between these two examinations. The China Conservatory of Music focuses on folk music, and the Central Conservatory of Music focuses on Western music. The piano is a Western musical instrument. Therefore, in fact, the piano grading examination at the Central Conservatory of Music is more valuable. If you are an expert, the examination certificate from the Central Conservatory of Music is generally recognized.

But now there is a problem, that is, the piano grading examination of China Conservatory of Music is divided into 10 levels, while the grading examination of Central Conservatory of Music is only level 9. Therefore, many laymen think that level 10 is more powerful than level 9, and they recognize level 10 more. In fact, this is not the case. A considerable part of the 10th-level examination repertoire of the China Conservatory of Music overlaps with the 9th-level repertoire of the Central Conservatory of Music. It can be seen that the level of difficulty of China Level 10 and Central Level 9 are similar.

I am not sure about the test center. But my hometown is a very small city, and there are both exams. If we can judge based on this experience, it should be applicable to both grades.