Não informado. (1927). Engineering and Mining Journal. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Não informado. Engineering and Mining Journal. New York: McGraw-Hill, 1927.
Lua MLA (8ú heag.)Não informado. Engineering and Mining Journal. McGraw-Hill, 1927.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.