Biblio
. Anon.1929. Reports on the Conferences of Cycles. Washington, D.C. : Carneige Institution.
. Anon.n.d. Dendrochronology and Studies in Cyclics. University of Pennsylvania Bicentennial Conference Proceedings. University of Pennsylvania Bicentennial Conference Proceedings.
. Anon.n.d. Dendrochronology and Studies in Cyclics. University of Pennsylvania Bicentennial Conference. University of Pennsylvania Bicentennial Conference.
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