Medicine and BooksBr Med J (Clin Res Ed) 1987; 294 doi: https://doi.org/10.1136/bmj.294.6570.503 (Published 21 February 1987) Cite this as: Br Med J (Clin Res Ed) 1987;294:503
Log in using your username and password
Log in through your institution
Register for a free trial to thebmj.com to receive unlimited access to all content on thebmj.com for 14 days.
Sign up for a free trial