ALERT: Before you purchase, check with your instructor or review your course syllabus to ensure that you select the correct ISBN. Several versions of Pearson's MyLab & Mastering products exist for each title, including customized versions for individual schools, and registrations are not transferable. In addition, you may need a CourseID, provided by your instructor, to register for and use Pearson's MyLab & Mastering products.NOTE: Make sure to use the dashes shown on the Access Card Code when entering the code.Student can use the URL and phone number below to help answer their questions: https: //support.pearson.com/getsupport/s/800-677-6337Packages Access codes for Pearson's MyLab & Mastering products may not be included when purchasing or renting from companies other than Pearson; check with the seller before completing your purchase.Used or rental books If you rent or purchase a used book with an access code, the access code may have been redeemed previously and you may have to purchase a new access code.Access codes Access codes that are purchased from sellers other than Pearson carry a higher risk of being either the wrong ISBN or a previously redeemed code. Check with the seller prior to purchase.0134841751 / 9780134841755 MasteringEnvironmentalScience with Pearson eText -- Standalone Access Card -- for Essential Environment: The Science Behind the Stories, 6/e Package consists of: 0134815521 / 9780134815527 MasteringEnvironmentalScience -- Pearson eText 2.0 Upgrade -- for Essential Environment: The Science Behind the Stories, 6/e 013481729X / 9780134817293 MasteringEnvironmentalScience Content -- Access Card Package Sales Accumulator -- for Essential Environment: The Science Behind the Stories, 6/e