APA (7e ed.) Bronvermelding

Ashenfelter, O., & Rouse, C. (1997). Income, schooling, and ability: Evidence from a new sample of identical twins. National Bureau of Economic Research.

Chicago (17e ed.) Bronvermelding

Ashenfelter, Orley, en Cecilia Rouse. Income, Schooling, and Ability: Evidence from a New Sample of Identical Twins. Cambridge: National Bureau of Economic Research, 1997.

MLA (9e ed.) Bronvermelding

Ashenfelter, Orley, en Cecilia Rouse. Income, Schooling, and Ability: Evidence from a New Sample of Identical Twins. National Bureau of Economic Research, 1997.