Ashenfelter, O., & Rouse, C. (1997). Income, schooling, and ability: Evidence from a new sample of identical twins. National Bureau of Economic Research.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Ashenfelter, Orley, و Cecilia Rouse. Income, Schooling, and Ability: Evidence from a New Sample of Identical Twins. Cambridge: National Bureau of Economic Research, 1997.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Ashenfelter, Orley, و Cecilia Rouse. Income, Schooling, and Ability: Evidence from a New Sample of Identical Twins. National Bureau of Economic Research, 1997.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.