PMI Practice Standards: are they useful to prepare PMP Certification?

Hi
Apart the PMBOK itself, which is the main source of information to prepare the PMP exam, do you think the other standards are useful?
I didn't consult them to prepare the PMP exam, but I'm reading them now with interest, as they provide a different approach and additional understanding of the topics.

Did you use one of several of these Practice standards to prepare your PMP exam?

1.       Project Manager Competency Development (PMCD) Framework (2^nd edition)

2.       Practice Standard for Earned Value Management

3.       Practice Standard for Project Configuration Management

4.       Practice standard for project risks management

5.       Practice Standard for Work Breakdown Structures (2^nd Edition)

6.       Practice standard for project estimating

7.       Practice standard for scheduling (2^nd Edition)

8.       The Standard for Program Management (2^nd Edition)

As a member of PMI, you can download these documents for free from PMI website.

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