tinbergen, j. (1962). the appraisal of investment projects: The semi input- output method. the institute of national planning.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)tinbergen, jan. The Appraisal of Investment Projects: The Semi Input- Output Method. cairo: the institute of national planning, 1962.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)tinbergen, jan. The Appraisal of Investment Projects: The Semi Input- Output Method. the institute of national planning, 1962.