MindTap Economics for 2-Semester Instant Access for Mankiw's Principles of Economics, 7th Edition This product requires a Course Key from your Instructor to fully activate. Please consult your Professor or class syllabus for the specific Course Key. ISBN: 9781285852447 Access to this product is valid for 365 days of usage. After this period, this product can be viewed under the "view expired" link in your CengageBrain account.