If you need a (not the full book but useful material), I recommend starting with:
C1 Writing Assessment Criteria Guide | PDF | Vocabulary - Scribd simply languagecert c1 pdf free
Downloading pirated material supports illegal distribution rather than the educators who create the content. Better Ways to Get Materials for Free If you need a (not the full book
If you are looking for a specific type of report—such as a breakdown or a Sample Writing Report for the C1 level—it is best to look at the "Expert C1" qualification handbooks provided by LanguageCert. there is good news:
However, there is good news: