Ordnance Survey Northern Ireland One-inch Series : 3rd edition outline.
Great Britain.Ordnance Survey.
Belfast : Ordnance Survey of Northern Ireland,
[1961-1968].
Relief shown by spot heights.
Sheet 1. North Coast (1961 ; 1966) -- Sheet 2. Londonderry (1962 ; 1967) -- Sheet 3. Mid Antrim (1965) -- Sheet 4. Omagh (1963 ; 1968) -- Sheet 5. East Tyrone (1964 ; 1967) -- Sheet 6. Belfast (1963) -- Sheet 7. Enniskillin (1963) -- Sheet 8. Armagh (1962 ; 1968) -- Sheet 9. South Down (1964).
refer to: C20(25A).
refer to: 32 (R. Hellyer: 1999).