- Callaham, R. Z. 1952a. Host selection and host susceptibility in western pine beetle-ponderosa pine complex. United States Department of Agriculture, Rureau of Entomology and Plant Quarantine, Forest Insect Laboratory, Rerkeley, California, Report. 8 p.
- Callaham, R. Z. 1952b. The role of quantitative oleoresin production in the susceptibility of pines to bark beetles. United States Department of Agriculture, Rureau of Entomology and Plant Quarantine, Forest Insect Laboratory, Rerkeley, California, Report. 8 P.
- Callaham, R. Z. 1953a. A technique for establishing attacks of isolated bark beetles. United States Department of Agriculture Rureau of Entomology and Plant Quarantine ET-311. 2 p.
- Callaham, R. Z. 1953b. Host specificity in the Dendroctonus-Pinus complex. United States Department of Agriculture, Rureau of Entomology and Plant Quarantine, Forest Insect Laboratory, Rerkeley, California, Special Report RX-11. 12 p.
- Callaham, R. Z. 1953c. Studies of the resistance of pines to bark beetle attacks, season of 1952. United States Department of Agriculture, Rureau of Entomology and Plant Quarantine, Forest Insect Laboratory, Rerkeley, California, Special Report RX-19. 27 p. (processed).
- Callaham, R. Z. 1955a. Oleoresin production in the resistance of ponderosa pine to bark beetles. United States Department of Agriculture, Forest Service, California Forest and Range Experiment Station, Report. 84 p.
- Callaham, R. Z. 1955b. Oleoresin production in the resistance of ponderosa pine to bark beetles. Unpublished dissertation, University of California, Rerkeley. 120 p.
- Callaham, R. Z. 1955c. Sapwood moisture associated with galleries of Dendroctonus valens . Journal of Forestry 53:916-917.
- Callaham, R. Z. 1966a. Nature of resistance of pines to bark beetles. NATO/NSF Advance Stud. Inst. Genet. Impr. Dis. Insect Resistance Forest Trees, Proc. 1964:197-206.
- Callaham, R. Z. 1966b. Needs in developing forest trees resistant to insects. NATO/NSF Advance Stud. Inst. Genet. Impr. Dis. Insect Resistance Forest Trees, Proc. 1964:469-476.
- Callaham, R. Z., and J. M. Miller. 1952. Studies of resistance of pine hybrids to bark beetle attacks, season of 1951. United States Department of Agriculture, Rureau of Entomology and Plant Quarantine, Forest Insect Laboratory, Rerkeley, California, Report. 31 p.
- Callaham, R. Z., and M. Shifrine. 1960. The yeasts associated with bark beetles . Forest Science 6:146-154.