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
Grieger KD, Sayes C, Hendron CO, Rothrock G, Mansfield C, Jayanty RKM, Ensor D. Finding the key to responsible nanomaterial development. Ehs Today: The Magazine For Environment, Health And Safety Leaders. 2013 Dec 6.