Biblio
“Reports On The Conferences Of Cycles”. Washington, D.C. : Carneige Institution.
. 1929. 
“Evidences Of Cycles In Tree Ring Records”. Proceedings Of The National Academy Of The Sciences. Proceedings Of The National Academy Of The Sciences.
. 1933. 
“Dendrochronology And Studies In Cyclics”. University Of Pennsylvania Bicentennial Conference Proceedings. University Of Pennsylvania Bicentennial Conference Proceedings.
. 