Christensen T, Riis AH, Hatch EE, Wise LA, Nielsen MG, Rothman KJ, Toft Sorensen H, Mikkelsen EM. Costs and efficiency of online and offline recruitment methods: a web-based cohort study. J Med Internet Res. 2017 Mar 1;19(3):e58. doi: 10.2196/jmir.6716
McElroy LM, Daud A, Davis AE, Lapin B, Baker T, Abecassis MM, Levitsky J, Holl JL, Ladner DP. A meta-analysis of complications following deceased donor liver transplant. Am J Surg. 2014 Oct;208(4):605-18. doi: 10.1016/j.amjsurg.2014.06.006