International Seminar on Approval and Gathering Plans in Large and Medium Size Academic Libraries, 3rd., West Palm Beach, Fla., 1971, Spyers-Duran, P., & Gore, D. (1972). Economics of approval plans: Proceedings. Greenwood Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रInternational Seminar on Approval and Gathering Plans in Large and Medium Size Academic Libraries, 3rd., West Palm Beach, Fla., 1971, Peter Spyers-Duran, और Daniel Gore. Economics of Approval Plans: Proceedings. Westport, Conn: Greenwood Press, 1972.
एमएलए (9वां संस्करण) प्रशस्ति पत्रInternational Seminar on Approval and Gathering Plans in Large and Medium Size Academic Libraries, 3rd., West Palm Beach, Fla., 1971, et al. Economics of Approval Plans: Proceedings. Greenwood Press, 1972.
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