BMJ. 1998 Jul 04;317(7150):45-7. doi: 10.1136/bmj.317.7150.45.
BMJ (Clinical research ed.)
C Webster
PMID: 9651271 PMCID: PMC1113451 DOI: 10.1136/bmj.317.7150.45 Free PMC Article
[No abstract available.]