United Nations Environment Programme & UNEP. Global Environment Outlook 3: Past, present and future perspectives. GEO-3: past, present and future perspectives.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)United Nations Environment Programme و UNEP. Global Environment Outlook 3: Past, Present and Future Perspectives. GEO-3: Past, Present and Future Perspectives. UNEP. EARTHSCAN.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)United Nations Environment Programme و UNEP. Global Environment Outlook 3: Past, Present and Future Perspectives. GEO-3: Past, Present and Future Perspectives.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.