David Card, O. A. (2011). Handbook of Labor Economics. ELSEVIER.
Lua i Stíl Chicago (17ú heag.)David Card, Orley Ashenfelter. Handbook of Labor Economics. ELSEVIER, 2011.
Lua MLA (8ú heag.)David Card, Orley Ashenfelter. Handbook of Labor Economics. ELSEVIER, 2011.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.