The online workbook / laboratory manual, produced in collaboration with Quia, offers the same outstanding practice as the printed Workbook / Laboratory Manual plus many additional advantages, such as onscreen links to corresponding audio files, immediate feedback and scoring for students, and an easy-to-use gradebook and class roster system for instructors. To gain access, students purchase a unique Student Book Key (passcode). Instructors should contact their local McGraw-Hill sales representative for an Instructor Book Key.