Williams, R. G. (1986). Export agriculture and the crisis in Central America. The University of North Carolina.
Lua i Stíl Chicago (17ú heag.)Williams, Robert G. Export Agriculture and the Crisis in Central America. Chapel Hill: The University of North Carolina, 1986.
Lua MLA (9ú heag.)Williams, Robert G. Export Agriculture and the Crisis in Central America. The University of North Carolina, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.