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
Purroy F, Cruz Esteve I, Galindo Ortego MG, Marsal Mora JR, Oro M, Plana A. Survey of the knowledge and management of transient ischemic attacks among primary care physicians and nurses. Neurologia. 2011 May;26(4):200-7. doi: 10.1016/j.nrl.2010.04.011