Robertson, W. D. (1942). The postage stamps of Ireland.
Lua i Stíl Chicago (17ú heag.)Robertson, W. D. The Postage Stamps of Ireland. 1942.
Lua MLA (9ú heag.)Robertson, W. D. The Postage Stamps of Ireland. 1942.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
