British Standards Institution. (1981). Mail processing machines. British Standards Institution.
Lua i Stíl Chicago (17ú heag.)British Standards Institution. Mail Processing Machines. London: British Standards Institution, 1981.
Lua MLA (9ú heag.)British Standards Institution. Mail Processing Machines. British Standards Institution, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
