Freeman, A. M. (2003). The measurement of environmental and resource values: Theory and methods (2nd ed.). Resources for the Future.
Chicago-referens (17:e uppl.)Freeman, A. Myrick. The Measurement of Environmental and Resource Values: Theory and Methods. 2nd ed. Washington, DC: Resources for the Future, 2003.
MLA-referens (8:e uppl.)Freeman, A. Myrick. The Measurement of Environmental and Resource Values: Theory and Methods. 2nd ed. Resources for the Future, 2003.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.