- Belluschi, P. G., and N. E. Johnson. 1969. The rate of crown fade of trees killed by the Douglas-fir beetle in southwestern Oregon . Journal of Forestry 67:30-32.
- Belluschi, P. G., N. E. Johnson, and H. J. Heikkenen. 1965. Douglas-fir defects caused by the Douglas-fir beetle . Journal of Forestry 63:252-256.
- Johnson, N. E., and P. G. Belluschi. 1969. Host-finding behavior of the Douglas-fir beetle . Journal of Forestry 67:290-295.