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Valderas JM, Starfield B, Forrest CB, Rajmil L, Roland M, Sibbald B.Valderas JM, et al. Among authors: starfield b.BMC Health Serv Res. 2009 Dec 4;9:221. doi: 10.1186/1472-6963-9-221.BMC Health Serv Res. 2009.PMID: 19961581Free PMC article.