Field EpidemiologyBr Med J 1950; 1 doi: https://doi.org/10.1136/bmj.1.4653.588 (Published 11 March 1950) Cite this as: Br Med J 1950;1:588
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