- Bergdahl, D. R. 1982. Occurrence of the pinewood nematode in eastern larch. Pages 47-55 in J. E. Appleby and R. B. Malek, Proceedings of the 1982 national pinewilt workshop, Rosemont, Illinois.
- Bergdahl, D. R., D. L. K. Smeltzer, and S. S. Halik. 1984. Components of a conifer wilt disease complex in the northeastern states [abstract]. Proceedings of the joint U.S.-Japan pine wilt disease seminar, Honolulu, Hawaii.
- Bergdahl, D. R., D. L. K. Smeltzer, and S. S. Halik. 1986. Components of a conifer wilt disease complex in the northeastern United States. Pages 152-157 in V. Dropkin, The resistance mechanisms of pines against pine wilt disease, 7-11 May 1984, Honolulu, Hawaii. Japan Society for the Promotion of Science.