Sayre, R. (2000). Nature in focus: Rapid ecological assessment. Island Press.
Cita Chicago (17th ed.)Sayre, Roger. Nature in Focus: Rapid Ecological Assessment. Island Press, 2000.
Cita MLA (9th ed.)Sayre, Roger. Nature in Focus: Rapid Ecological Assessment. Island Press, 2000.
Atenció: Aquestes cites poden no estar 100% correctes.