Orr, D. W. (2011). Hope is an imperative: The essential David Orr. Island Press.
Style de citation Chicago (17e éd.)Orr, David W. Hope Is an Imperative: The Essential David Orr. Washington, DC: Island Press, 2011.
Style de citation MLA (9e éd.)Orr, David W. Hope Is an Imperative: The Essential David Orr. Island Press, 2011.
Attention : ces citations peuvent ne pas être correctes à 100%.