Christopherson, Robert W. Geosystems : an introduction to physical geography/ Robert W. Christopherson. - 5th ed. - Upper Saddle River, N.J. : Pearson Prentice Hall, 2005. - xix, 660p. : ill. student guide Includes index. ISBN: 0131475401 Subjects--Topical Terms: Physical geography. LC Class. No.: GB 54.5 CHR 2005