Research Article
A hundred and still going strong.
Br Med J (Clin Res Ed) 1982; 284 doi: https://doi.org/10.1136/bmj.284.6332.1816 (Published 19 June 1982) Cite this as: Br Med J (Clin Res Ed) 1982;284:1816This is a PDF-only article. The first page of the PDF of this article appears above.