- Choo, H. Y., H. K. Kaya, P. Shea, and E. M. Noffsinger. 1987. Ecological study of nematode parasitism in Ips beetles from California and Idaho. Journal of Nematology 19:495-502.
- Choo, H. Y., H. K. Kaya, P. Shea, and E. M. Noffsinger. 1987. Ecological study of nematode parasitism in Ips beetles from California and Idaho . Journal of Nematology 19:495-502.