George Allen & Unwin Ltd. (1994). How things work: The universal encyclopedia of Machines Vol. II. Harper Collins Publications.
Lua i Stíl Chicago (17ú heag.)George Allen & Unwin Ltd. How Things Work: The Universal Encyclopedia of Machines Vol. II. New delhi: Harper Collins Publications, 1994.
Lua MLA (9ú heag.)George Allen & Unwin Ltd. How Things Work: The Universal Encyclopedia of Machines Vol. II. Harper Collins Publications, 1994.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.