Letters to the Editor

Quinn N Hallett M . Dose standardisation of botulinum toxin. Lancet 1989;330:964.

Schantz EJ Johnson EA . Dose standardisation of botulinum toxin. Lancet 1990;335:421.

Miles AA . Biological standards and the measurement of therapeutic activity. Br Med Bull 1951;7:283–91.

Wilks CGW . Treatment of a dental phobic with pronounced aversion to rubber gloves by swallowing relaxation in two appointments. Br Dent J 1993;175:88–9.

PADI. Open Water Diver Manual, 1st edn. California: PADI, 1990:16.

Sport Diving. The British Sub-Aqua Club Diving Manual, 15th edn. London: Stanley Paul & Co., 1991:33.

Brown MJ Jones J Krohmer . Pseudoephedrine for the prevention of barotitis media: A controlled clinical trial in underwater divers. Ann Emerg Med 1992;21:849–52.