1. ANON (1994)Beekeeping and health statistics.Ministry of Agriculture Fisheries and Food; London, UK; 7 pp.
2. ANON (1995)The digest of agricultural census statistics 1994.HMSO; London, UK; 131 pp.
3. HOWES, F N (1979)Plants and beekeeping.Faber & Faber; London, UK; 236 pp (2nd edition). 202/80
4. STACE, C (1995) Newflora of the British Isles.Cambridge University Press; Cambridge, UK; 1226 pp.