Swetnam, T. 1987. ?A Dendrochronological Assessment Of Western Spruce Budworm, Choristoneura Occidentalis Freeman, In The Southern Rocky Mountains?. School Of Renewable Natural Resources. School Of Renewable Natural Resources. University of Arizona. http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=753027921&sid=16&Fmt=2&clientId=43922&RQT=309&VName=PQD.