editorial . 2004 May 20;33(4):628–634. doi: 10.1093/ije/dyh198
IJE vol.33 no.4 © International Epidemiological Association 2004; all rights reserved.
This article is made available via the PMC Open Access Subset for unrestricted re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the COVID-19 pandemic or until permissions are revoked in writing. Upon expiration of these permissions, PMC is granted a perpetual license to make this article available via PMC and Europe PMC, consistent with existing copyright protections.