I used the practice exams and study guide for AWS SAP C01. The questions of the practice exams are well aligned with the syllabus and the content is updated as well. The explanations are accurate and the references to white papers and documentation is helpful as well. I purchased the study guide as well. It was really helpful as it had summarized content for various aspects of the exam. viz. Design for Org. Complexity, Migration etc. Overall a must have to clear the exam with ease.