Freeman, A. M. (2003). The measurement of environmental and resource values: Theory and methods (2nd ed.). Resources for the Future.
Cita Chicago (17th ed.)Freeman, A. Myrick. The Measurement of Environmental and Resource Values: Theory and Methods. 2nd ed. Washington, DC: Resources for the Future, 2003.
Cita MLA (8th ed.)Freeman, A. Myrick. The Measurement of Environmental and Resource Values: Theory and Methods. 2nd ed. Resources for the Future, 2003.
Atenció: Aquestes cites poden no estar 100% correctes.