You can use any content review book you’d like alongside our course. We’ve carefully matched up the Kaplan and Princeton chapters and sections with the associated lesson of our Free eCourse, but you could easily match up any content review book you’d like. Simply watch the videos from the lesson of our Free eCourse and then read the sections from your content review book that relate to the topics discussed. We’ve had students use many different content review books while working through our course.