Epidemiology SectionBr Med J 1947; 1 doi: https://doi.org/10.1136/bmj.1.4509.831 (Published 07 June 1947) Cite this as: Br Med J 1947;1:831
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