World Health Research CentreBr Med J 1964; 1 doi: http://dx.doi.org/10.1136/bmj.1.5399.1653 (Published 27 June 1964) Cite this as: Br Med J 1964;1:1653
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