Philippines. National Statistical Coordination Board, Regional Unit I. Regional social and economic trends: Region 1 (Ilocos Region). Regional Unit I, National Statistical Coordination Board.
Παραπομπή σε μορφή Chicago (17η εκδ.)Philippines. National Statistical Coordination Board, Regional Unit I. Regional Social and Economic Trends: Region 1 (Ilocos Region). La Union: Regional Unit I, National Statistical Coordination Board.
Παραπομπή σε μορφή MLA (9th εκδ.)Philippines. National Statistical Coordination Board, Regional Unit I. Regional Social and Economic Trends: Region 1 (Ilocos Region). Regional Unit I, National Statistical Coordination Board.
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