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Ward, J. D., E. T. Wilson, and W. E. McDowell. An Evaluation of Southern Pine Beetle Infestations on the Great Smoky Mountains National Park. Asheville, NC: U.S. Forest Service, 1971.

Ward, J. D., and W. E. McDowell. An Evaluation of Southern Pine Beetle Infestations, Great Smoky Mountains National Park in Tennessee and North Carolina. Asheville, NC: U.S. Forest Service, 1970.