Philippines. National Economic and Development Authority. Regional Development Council, Region I. (1976). Demographic profile on Region I: A study on population growth, composition and employment. The Council.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Philippines. National Economic and Development Authority. Regional Development Council, Region I. Demographic Profile on Region I: A Study on Population Growth, Composition and Employment. San Fernando, La Union: The Council, 1976.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Philippines. National Economic and Development Authority. Regional Development Council, Region I. Demographic Profile on Region I: A Study on Population Growth, Composition and Employment. The Council, 1976.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.