BMJ. 1991 Feb 23;302(6774):470.
BMJ (Clinical research ed.)
[No authors listed]
PMID: 2053952 PMCID: PMC1669358 Free PMC Article
[No abstract available.]
Drèze J. Natl Med J India. 1999 Jan-Feb;12(1):2-5. PMID: 10326321