APA-referens (7:e uppl.)
Orr, D. W. (2011). Hope is an Imperative: The Essential David Orr. Island Press/Center for Resource Economics. https://doi.org/10.5822/978-1-61091-017-0
Chicago-referens (17:e uppl.)
Orr, David W. Hope Is an Imperative: The Essential David Orr. Washington, DC: Island Press/Center for Resource Economics, 2011. https://doi.org/10.5822/978-1-61091-017-0.
MLA-referens (9:e uppl.)
Orr, David W. Hope Is an Imperative: The Essential David Orr. Island Press/Center for Resource Economics, 2011. https://doi.org/10.5822/978-1-61091-017-0.
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