Keith, N. W., & Keith, N. Z. (1988). New perspectives on social class and socioeconomic development in the periphery. Greenwood Press.
Lua i Stíl Chicago (17ú heag.)Keith, Nelson W., agus Novella Zett Keith. New Perspectives on Social Class and Socioeconomic Development in the Periphery. New York: Greenwood Press, 1988.
Lua MLA (8ú heag.)Keith, Nelson W., agus Novella Zett Keith. New Perspectives on Social Class and Socioeconomic Development in the Periphery. Greenwood Press, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.