Bergman, Edward F. Introduction to geography / Edward F. Bergman, Tom L. McKnight. - Englewood Cliffs, NJ : Prentice Hall, 1993. - xv, 472 p. : ill. (some col.) ; 28 cm. ISBN: 013472416X LCCN: 92026294 LC Class. No.: G128 .B37 1993 / .B37 1993 Dewey Class. No.: 910