Painter & Ashe 2012: "The work by McCright and Dunlap has highlighted the effectiveness of organized climate sceptic groups in influencing US policy making in the 1990s and early 2000s, including their central role in the rejection of the Kyoto Protocol by the US Congress" Brulle, Robert J. (21 December 2013).
Truy cập ngày 2 tháng 8 năm 2007.  ^ Painter & Ashe 2012: "The work by McCright and Dunlap has highlighted the effectiveness of organized climate sceptic groups in influencing US policy making in the 1990s and early 2000s, including their central role in the rejection of the Kyoto Protocol by the US Congress" ^ Brulle, Robert J. (21 tháng 12 năm 2013).