Keith-Lucas, A. (1972). Giving and taking help. University of North Carolina.
Lua i Stíl Chicago (17ú heag.)Keith-Lucas, Alan. Giving and Taking Help. Chapel hill: University of North Carolina, 1972.
Lua MLA (9ú heag.)Keith-Lucas, Alan. Giving and Taking Help. University of North Carolina, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.