United Nations Environment Programme. Division of Early Warning and Assessment. (2006). Geo year book 2006: An overview of our changing environment. UNEP Division of Early Warning and Assessment.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)United Nations Environment Programme. Division of Early Warning and Assessment. Geo Year Book 2006: An Overview of Our Changing Environment. Nairobi: UNEP Division of Early Warning and Assessment, 2006.
Trích dẫn kiểu MLA (xuất bản lần thứ 9)United Nations Environment Programme. Division of Early Warning and Assessment. Geo Year Book 2006: An Overview of Our Changing Environment. UNEP Division of Early Warning and Assessment, 2006.
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