Dulfer, E. (1974). Operational efficiency of agricultural cooperatives in developing countries. Food and Agriculture Organization of the United Nations.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Dulfer, Eberhard. Operational Efficiency of Agricultural Cooperatives in Developing Countries. Rome: Food and Agriculture Organization of the United Nations, 1974.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Dulfer, Eberhard. Operational Efficiency of Agricultural Cooperatives in Developing Countries. Food and Agriculture Organization of the United Nations, 1974.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.