Philippines (Republic) Office of Manpower Services. Employment Service Division. (1957). Philippine occupational classification with titles, codes and definitions. s.n.
Chicago-viite (17. p.)Philippines (Republic) Office of Manpower Services. Employment Service Division. Philippine Occupational Classification with Titles, Codes and Definitions. 224p.,Manila: s.n, 1957.
MLA-viite (9. p.)Philippines (Republic) Office of Manpower Services. Employment Service Division. Philippine Occupational Classification with Titles, Codes and Definitions. s.n, 1957.
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