IRELAND'S TRANSITION - POSTAL HISTORY 1922-1925, C.I. Dulin, 1992 (hardback)
Very scarce, the definitive work on The Postal History of the Transitional Period, 1922-1925, by Dr C.I. Dulin of Geneva, published by Macdonnell Whyte in Dublin in 1992. 394pp.
This is a comprehensive and well illustrated work covering the Treaty Period of December 1921 up to Transition in 1925, with chapters on stamps of the Irish Free State, the Civil War, Postal Stationery, Postage Dues, Official Paids, Military Mail, Airmail and Railway Post, and many other areas. Hard to find; a well preserved copy with dust jacket.