ALCOCK, R. (1986). Tractor-implement systems. AVI.
Lua i Stíl Chicago (17ú heag.)ALCOCK, Ralph. Tractor-implement Systems. Westport: AVI, 1986.
Lua MLA (9ú heag.)ALCOCK, Ralph. Tractor-implement Systems. AVI, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.