McCord, Virgil Alexander Stuart. 1984. ?A New Computerized X-Ray Densitometric System For Tree-Ring Analysis?. Geoscience. Geoscience. University of Arizona. http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=753909891&sid=1&Fmt=1&clientId=43922&RQT=309&VName=PQD.