Heywood, D. Ian. An introduction to geographical information systems / Ian Heywood, Sarah Cornelius, Steve Carver. - 3rd ed. - Harlow, England ; New York : Pearson Prentice Hall, 2006. - xxxiii, 426 p. : col. ill. ; 27 cm. Includes bibliographical references and index. ISBN: 9780131293175 Subjects--Topical Terms: Geographic information systems. Dewey Class. No.: 910.285 / H D I