Schultz, T. W. (1981). Investing in people: The economics of population quality. University of California.
Lua i Stíl Chicago (17ú heag.)Schultz, Theodore W. Investing in People: The Economics of Population Quality. London: University of California, 1981.
Lua MLA (9ú heag.)Schultz, Theodore W. Investing in People: The Economics of Population Quality. University of California, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.