In recent times, the PMP certification exam has notably grown more challenging compared to studying PMBOK. However, it now necessitates the utilization of additional resources. Which resources are required and where can they be located? Saving Changes...
The PMP exam always covered more than just the content of the PMBOK Guide. The CAPM exam was purely based on the PMBOK Guide.
I always recommend starting with the Exam Content Outline to understand what you will be tested on and then cross-reference that against the list of reference documents available on this web page: https://www.pmi.org/certifications/project...xam-preparation
You can also look into a PMP Prep course which will provide its own study materials or a self-study guide from a quality provider.