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Reinders ME, Blankenstein AH, van Marwijk HW, Knol DL, Ram P, van der Horst HE, de Vet HC, van der Vleuten CP.Reinders ME, et al. Among authors: knol dl.Med Educ. 2011 Jun;45(6):578-84. doi: 10.1111/j.1365-2923.2010.03917.x.Med Educ. 2011.PMID: 21564197
Mokkink LB, Terwee CB, Gibbons E, Stratford PW, Alonso J, Patrick DL, Knol DL, Bouter LM, de Vet HC.Mokkink LB, et al. Among authors: knol dl.BMC Med Res Methodol. 2010 Sep 22;10:82. doi: 10.1186/1471-2288-10-82.BMC Med Res Methodol. 2010.PMID: 20860789Free PMC article.