Br Med J (Clin Res Ed). 1987 May 23;294(6583):1350-1. doi: 10.1136/bmj.294.6583.1350.
British medical journal (Clinical research ed.)
[No authors listed]
PMID: 3109647 PMCID: PMC1246501 DOI: 10.1136/bmj.294.6583.1350 Free PMC Article
[No abstract available.]