Book excerpt: Note: If you are purchasing an electronic version, MasteringGeography does not come automatically packaged with it. To purchase MasteringGeography, please visitwww.MasteringGeography.com or you can purchase a package of the physical text and MasteringGeography by searching for ISBN 10: 0133405524 / ISBN 13: 9780133405521. Respected for its scientific accuracy, currency and thoroughness, and for its integration of high quality figures and photos, Christopherson/Byrne/Giles, Geosystems Fourth Canadian edition is the name you can trust with the content your students will read.