Both this list and the CIA list may contain further errors. Despite the claim by the CIA that their list was updated in July 2006, none of the errors listed on the talk page have been corrected. World Tops and Bottoms, by Grant Hutchison, 1996, TACit Press, ISBN 0-9522680-4-3, and subsequent research by the same author, in collaboration with field research by Ginge Fullen.