1. Emson, R. H. & Wilkie, I. C. Oceanogr. mar. Biol. A. Rev. 18, 155–250 (1980).
2. Hughes, R. N. & Cancino, J. M. in Population Biology and Evolution of Clonal Organisms (eds Jackson, J. B. C., Buss, L. W. & Cook, R. E.) 153–186 (Yale University Press, New York, 1985).
3. Lawrence, J. M. A Functional Biology of Echinoderms (Johns Hopkins University Press, Maryland, 1987).
4. Komatsu, M. et al. in Echinoderms: Proceedings of the International Conference, Tampa Bay (ed. Lawrence, J. M.) 497–503 (Balkema, Rotterdam, 1982).
5. Strathmann, R. R. J. exp. mar. Biol. Ecol. 6, 109–160 (1971).