Closer ContactBr Med J 1952; 2 doi: https://doi.org/10.1136/bmj.2.4788.822 (Published 11 October 1952) Cite this as: Br Med J 1952;2:822
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