1. Arneberg P, Skorping A, Grenfell B, Read AF (1998) Host densities as determinants of abundance in parasite communities. Proc R Soc Lond B 265:1283–1289
2. Beaver PC, Jung RC, Cupp EW (1984) Clinical parasitology, 9th ed. Lea & Febiger, Philadelphia, PA
3. Brown DS (1978) Pulmonate molluscs as intermediate hosts for digenetic trematodes. In: Fretter V, Peake J (eds) Pulmonates. Academic Press, New York, NY, pp 287–333
4. Calow E (1993) Handbook of ecotoxicology. Blackwell Scientific Publications, Oxford, UK
5. Chappell LH, Hardie LJ, Secombes CJ (1994) Diplostomiasis: the disease and host-parasite interactions. In: Pike AW, Lewis JW (eds) Parasitic diseases of fishes. Samara Publishing, Tresaith, Dyfed, West Wales