Legislación postal : contestaciones al programa de ingreso en el cuerpo ejecutivo de correos / D. Ramón Martínez Gahete y D. Sergio Bermejo Esteban
Boletim oficial : índice remissivo: 1970/76 / Correios e Telecomunicações de Portugal
Postmarks of South West Africa Under South African Administration : A comprehensive study 1914 - 1977 Including a complete listing of all S.W.A. Post Offices with a special sections on S. African military campaign postmarks 1914-1915 railways sations cacellations 1915 - 1977 telegraph Stations, airmail history of S.W.A. cencor cachets, ships postmarks, etc. / Ralph F. Putzel