Ashton, J., Ritson, C., & Harvey, D. R. (1991). The Common agricultural policy and the world economy: Essays in honour of John Ashton. C·A·B International.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रAshton, J., Christopher Ritson, और David R. Harvey. The Common Agricultural Policy and the World Economy: Essays in Honour of John Ashton. Wallingford, Oxon, UK: C·A·B International, 1991.
एमएलए (8वां संस्करण) प्रशस्ति पत्रAshton, J., et al. The Common Agricultural Policy and the World Economy: Essays in Honour of John Ashton. C·A·B International, 1991.
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