Nayyar, G. (2009). The Demand for Services in India. A Mirror Image of Engel's Law for Food? Department of Economics (University of Oxford).
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Nayyar, G. The Demand for Services in India. A Mirror Image of Engel's Law for Food? Department of Economics (University of Oxford), 2009.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Nayyar, G. The Demand for Services in India. A Mirror Image of Engel's Law for Food? Department of Economics (University of Oxford), 2009.
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