1. Abbott, D. P. and Haderlie, E. C. (1980) Prosobranchia: marine snails. In Intertidal Inverterbrates of California (eds, R. H. Morris, D. P. Abbott and E. C. Haderlie), Stanford University press, Stanford, California, pp. 230–307.
2. Adams, J. E. and Martin, W. E. (1963) Life cycle of Himasthla rhigedana Dietz, 1909 (Trematoda: Echinostomatidae). Trans. Am. Micros. Soc., 82, 1–6.
3. Anteson, R. K. (1970) On the resistance of the snail, Lymnaea catascopium pallid (Adams) to concurrent infection with sporocysts of the strigeid trematode, Cotylurus flabelliformis (Faust) and Diplostomum flexicaudum (Cort and Brooks). Ann. Trop. Med. Parasitol., 64, 101–7.
4. Askew, R. R. and Shaw, M. R. (1986) Parasitoid communities: their size, structure and development. In Insect Parasitoids, (eds, J. Waage and D. Greathead), Academic Press, London, pp. 225–64.
5. Basch, P. F. and Lie, K. J. (1966) Infection of single snails with two different trematodes. I. Simultaneous exposure and early development of a schistosome and an echinostome. Z. Parasitenk., 27, 252–9.