1. Anderson, D. T., 1966, Arthropod arboriculture, Ann. Mag. Nat. Hist. Ser. 13 9:445–456.
2. Anderson, D. T., 1973, Embryology and Phylogeny of Annelids and Arthropods, Pergamon Press, Oxford.
3. Barnes, R. D., 1968, Invertebrate Zoology, 2nd ed., Saunders, Philadelphia, Pa. Calman, W. T., 1936, The origin of insects, Proc. Linn. Soc. London 1935–1936: 193–204.
4. Cisne, J. L., 1974, Trilobites and the origin of arthropods, Science 186: 13–18.
5. Hedgepeth, J. W., 1954, On the phylogeny of the Pycnagonida, Acta Zool. (Stockholm) 35:193–213. Imms, A. D., 1936, The ancestry of insects, Trans. Soc. Br. Entomol. 3: 1–32.