Philippines (Republic) Office of Manpower Services. Employment Service Division. (1957). Philippine occupational classification with titles, codes and definitions. s.n.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Philippines (Republic) Office of Manpower Services. Employment Service Division. Philippine Occupational Classification with Titles, Codes and Definitions. 224p.,Manila: s.n, 1957.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Philippines (Republic) Office of Manpower Services. Employment Service Division. Philippine Occupational Classification with Titles, Codes and Definitions. s.n, 1957.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.