This is the list of AWS Publications given by AWS as reference material for the CWI Exam. They can be pricey but are included when you attend a Seminar/Exam session.
When you check the website you will see that the exact year publication may be more expensive than other years. I have many certifications and I usually use older study materials.
The majority of the information is presented in our training materials in one way or another. These are not required when taking the actual exam and may slow you down anyway. AWS provides all necessary information for reference during the exams.
I initially got certified by just studying the Certification Manual. It includes most of the relevant information in the other publications.
You can access these at AWS book store
