- Robertson, R. L., and F. E. Whitfield. 1968a. Southern pine beetle of North Carolina. North Carolina University, Extension Folder 274. 6 p. (revised 1975).
- Robertson, R. L., and F. E. Whitfield. 1968b. The engraver beetle in North Carolina. North Carolina University, Extension Folder 272. 8 p.
- Robertson, R. L., and F. E. Whitfield. 1968c. The turpentine beetle in North Carolina. North Carolina University, Extension Folder 273. 8 p.