^"The 10/40 Window". Time Magazine. June 30, 2003. تمت أرشفته من الأصل في April 28, 2007. اطلع عليه بتاريخ March 1, 2007.الوسيط |وصلة مكسورة= تم تجاهله (مساعدة). The link is to the map, which is part of an extensive cover story.
^World FactBook.الوسيط |العنوان= تم تجاهله (مساعدة), edition available in 1990. At the time, the authoritative source for socioeconomic and political metrics for every nation. Extreme poverty was denoted as under US$500 per capita GNP (in 1990 dollars). Human suffering was measured by the Quality of Life index, precursor to today's مؤشر التنمية البشرية
^See the Analysis section of this article for research-based details and cited references.