Duffy, J. (1876). Letter on diamond drill.
Lua i Stíl Chicago (17ú heag.)Duffy, John. Letter on Diamond Drill. 1876.
Lua MLA (9ú heag.)Duffy, John. Letter on Diamond Drill. 1876.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
