- Smith, J. D., and D. B. Twardus. 1979. Evaluation of a southern pine beetle control tactic: a case study for symposium participants. Pages 106-111 in J. E. Coster and J. L. Searcy, (eds.), Evaluating control tactics for the southern pine beetle. United States Department of Agriculture, Forest Service, Technical Bulletin 1613. 118 p.
- Twardus, D. B. 1976. Current status of southern pine beetle threat . Forest Farmer 3624, 34.
- Twardus, D. B. 1977a. Current status of the southern pine beetle and postsuppression evaluation in the Red Dirt Study Area, Kisatchie National Forest. United States Department of Agriculture, Forest Service, Southern Region, Forest Pest Management, Report 77-2-3.
- Twardus, D. B. 1977b. Evaluation of southern pine beetle infestation on the National Forests in Mississippi. United States Department of Agriculture, Forest Service, Southern Region, Forest Pest Management, Report 78-2-7.
- Twardus, D. B. 1977c. Reevaluation of the southern pine beetle status of the Strong River District, Bienville National Forest. United States Department of Agriculture, Forest Service, Southern Region, Forest Pest Management, Report 77-2-6.
- Twardus, D. B., and G. D. Hertel. 1978a. Evaluation of southern pine beetle infestation on the National Forest in Mississippi. United States Department of Agriculture, Forest Service, Southern Region, Forest Pest Management, Report 78-2-7.
- Twardus, D. B., and G. D. Hertel. 1978b. Preliminary evaluation of the effects of felling a buffer strip of southern pine beetle infestation breakout and proliferation. United States Department of Agriculture, Forest Service, Southern Region, Forest Pest Management, Report 78-2-9.
- Twardus, D. B., G. D. Hertel, and G. W. Ryan. 1978. Southern pine beetle infestation, growth, and decline, 1977. United States Department of Agriculture, Forest Service, Southern Region, Forest Pest Management, Report 78-2-8.