Br Med J (Clin Res Ed). 1981 Jun 27;282(6282):2135-6. doi: 10.1136/bmj.282.6282.2135-d.
British medical journal (Clinical research ed.)
[No authors listed]
PMID: 6788237 PMCID: PMC1506484 DOI: 10.1136/bmj.282.6282.2135-d
[No abstract available.]