Keifer, MaryBeth. 1991. ?Age Structure And Fire Disturbance In The Southern Sierra Nevada Subalpine Forest?. Biology. Biology. University of Arizona. http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=747829851&sid=7&Fmt=2&clientId=43922&RQT=309&VName=PQD.