Cita APA (7th ed.)
United Nations Environment Programme & UNEP. Global Environment Outlook 3: Past, present and future perspectives. GEO-3: past, present and future perspectives.
Cita Chicago (17th ed.)
United Nations Environment Programme i UNEP. Global Environment Outlook 3: Past, Present and Future Perspectives. GEO-3: Past, Present and Future Perspectives. UNEP. EARTHSCAN.
Cita MLA (9th ed.)
United Nations Environment Programme i UNEP. Global Environment Outlook 3: Past, Present and Future Perspectives. GEO-3: Past, Present and Future Perspectives.
Atenció: Aquestes cites poden no estar 100% correctes.