Mayyasi, A. M., P. E. Pulley, R. N. Coulson, D. W. DeMichele, and J. L. Foltz. 1976. Mathematical description of within-tree distributions of the various developmental stages of Dendroctonus frontalis Zimm (Coleoptera: Scolytidae). Researches on Population Ecology (Kyoto) 18:135-145.