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Herrett EL, Thomas SL, Smeeth L.Herrett EL, et al.Br J Gen Pract. 2011 Jul;61(588):438-9. doi: 10.3399/bjgp11X583092.Br J Gen Pract. 2011.PMID: 21722461Free PMC article.No abstract available.
Herrett E, Shah AD, Boggon R, Denaxas S, Smeeth L, van Staa T, Timmis A, Hemingway H.Herrett E, et al.BMJ. 2013 May 20;346:f2350. doi: 10.1136/bmj.f2350.BMJ. 2013.PMID: 23692896Free PMC article.