Tippins, H.H., & Beshear, R.J. 1968 Variations in the number and groupings of disc pores in Comstockiella sabalis (Comst.) (Homoptera: Diaspididae).. Journal of the Georgia Entomological Society 3: 67-69.

Notes: Recognizes four types based on number of perivulvular pore groups and on number of pores in each group.