Underdown, R. B. Ground studies for pilots. Navigation / Navigation R.B. Underdown - 6th ed. - Malden, MA : Blackwell Science, 2001. - xiii, 362 p. : ill. ; - Ground studies for pilots series . Includes index. ISBN: 063205333X Subjects--Topical Terms: Navigation (Aeronautics) LC Class. No.: TL586 / .U53 2001