Freeman, A. M. (2003). The measurement of environmental and resource values: Theory and methods (2nd ed.). Resources for the Future.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रFreeman, A. Myrick. The Measurement of Environmental and Resource Values: Theory and Methods. 2nd ed. Washington, DC: Resources for the Future, 2003.
एमएलए (8वां संस्करण) प्रशस्ति पत्रFreeman, A. Myrick. The Measurement of Environmental and Resource Values: Theory and Methods. 2nd ed. Resources for the Future, 2003.
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