Centre for Educational Research and Innovation, Bottomley, J. A., & Dunworth, J. E. (1972). Costs and potential economies. Organisation for Economic Co-operation and Development.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Centre for Educational Research and Innovation, J. A. Bottomley, و J. E. Dunworth. Costs and Potential Economies. Paris: Organisation for Economic Co-operation and Development, 1972.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Centre for Educational Research and Innovation, et al. Costs and Potential Economies. Organisation for Economic Co-operation and Development, 1972.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.