@conference {709, title = {Tree Growth and Solar Cycles}, booktitle = {Paper Presented at International Research Council}, year = {1931}, note = {Copies of this are available through the Tree Ring Laboratory. Please contact the curator for more information. pcreasman@ltrr.arizona.edu}, keywords = {astronomy, Douglass, historic, solar cycles, tree growth}, author = {Douglass, A.E.} }