Birdsall, N. (1993). Population growth, externalities, and poverty. Policy Research Department and Eastern African Department, World Bank.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Birdsall, Nancy. Population Growth, Externalities, and Poverty. Washington, D.C: Policy Research Department and Eastern African Department, World Bank, 1993.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Birdsall, Nancy. Population Growth, Externalities, and Poverty. Policy Research Department and Eastern African Department, World Bank, 1993.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.