This is a set of text & workbook and DVD to deepen your knowledge of developmental disabilities. Thank you for viewing. Human Resource Certification Association Child Development Support Specialist Text & Workbook & DVD - Complete 3-piece set This is the official text used in correspondence courses, and you cannot obtain certification by purchasing only this material secondhand. Please be aware that to obtain certification, you must apply for the official correspondence course, complete the curriculum, and purchase the materials from the official source to be eligible to take the exam. Recommended for those who only want to study or want to see what the content is like. The workbook has no writing in it, but the text has underlining on a few pages, so please purchase only if you can accept this.