Wright, William Edward. 2001. ?Delta-Deuterium And Delta-Oxygen-18 In Mixed Conifer Systems In The United States Southwest: The Potential Of Delta-Oxygen-18 In Pinus Ponderosa Tree Rings As A Natural Environmental Recorder?. Geoscience. Geoscience. University of Arizona. http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=728996441&sid=11&Fmt=2&clientId=43922&RQT=309&VName=PQD.