1. Alford, D. V. (1984).A colour atlas of fruit pests: their recognition, biology and control.Wolfe Publishing Ltd., London.
2. Anon. (1991).Multi-year crop protection plan. Government decision 1991.Ministry of Agriculture, Nature Management & Fisheries (The Netherlands).
3. Anon. (1996). Food of the future.Which? July, 22–4.
4. Barnes, H. F. (1948).Gall midges of economic importance. III. Gall midges of fruit.Crosby Lockwood, London.
5. Bevan, D. (1987).Forest insects: a guide to insects feeding on trees in Britain.Forestry Commission Handbook 1. HMSO: London.