Cita APA (7th ed.)
United Nations Environment Programme & UNEP. Global Environment Outlook 4: Evironment for development. GEO-4: evironment for development.
Cita Chicago (17th ed.)
United Nations Environment Programme i UNEP. Global Environment Outlook 4: Evironment for Development. GEO-4: Evironment for Development. UNEP. EARTHSCAN.
Cita MLA (9th ed.)
United Nations Environment Programme i UNEP. Global Environment Outlook 4: Evironment for Development. GEO-4: Evironment for Development.
Atenció: Aquestes cites poden no estar 100% correctes.