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Anderson HR, Ayres JG, Sturdy PM, Bland JM, Butland BK, Peckitt C, Taylor JC, Victor CR.Anderson HR, et al. Among authors: butland bk.BMJ. 2005 Jan 15;330(7483):117. doi: 10.1136/bmj.38316.729907.8F. Epub 2004 Dec 23.BMJ. 2005.PMID: 15618231Free PMC article.
Butland BK, Strachan DP, Anderson HR.Butland BK, et al.Eur Respir J. 1999 Apr;13(4):744-50. doi: 10.1034/j.1399-3003.1999.13d08.x.Eur Respir J. 1999.PMID: 10362034Free article.