[1]Approximate dating. Exact dating by the methods of tree-ring
chronology are yet to be accomplished.
[2]The Secret of the Southwest Solved by Talkative Tree Rings, by A. E.
Douglass: National Geographic Magazine, December 1929.
[3]For complete bibliography apply at the park museum or write to the
Superintendent, Mesa Verde National Park.
[4]Copies in Mesa Verde Museum Library.