Schafale, Michael P., and Charlotte Pyle. "Land Use History of Three Spruce-Fir Forest Sites in Southern Appalachia." Journal of Forest History 32, no. 1 (1988): 4-21.

Pyle, Charlotte, and Michael P. Schafale. History of Disturbance in Spruce-fir Forests of the SARRMC Intensive Study Sites -- Mt. Rogers National Recreation Area, Black Mountains, and Great Smoky Mountains. Southern Appalachian Spruce-fir Ecosystem Assessment Program, 1985.

Pyle, Charlotte. Pre-Park Disturbance in the Spruce-Fir Forests of Great Smoky Mountains National Park In The Southern Appalachian Spruce-Fir Ecosystem: Its Biology and Threats. Gatlinburg, TN: Uplands Field Research Laboratory, 1984.