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.
Παραπομπή σε μορφή Chicago (17η εκδ.)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.
Παραπομπή σε μορφή MLA (9th εκδ.)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.
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