Points: Urban MarksBr Med J (Clin Res Ed) 1984; 288 doi: http://dx.doi.org/10.1136/bmj.288.6414.408-g (Published 04 February 1984) Cite this as: Br Med J (Clin Res Ed) 1984;288:408
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