Biblio
. 1929. “Reports On The Conferences Of Cycles”. Washington, D.C. : Carneige Institution.
. “Dendrochronology And Studies In Cyclics”. University Of Pennsylvania Bicentennial Conference Proceedings. University Of Pennsylvania Bicentennial Conference Proceedings.
. “Dendrochronology And Studies In Cyclics”. University Of Pennsylvania Bicentennial Conference. University Of Pennsylvania Bicentennial Conference.

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