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
Chirila C, Earnshaw SR, Black L, McDade CL, Roskell NS, Shannon PR, Montorsi F, Andriole GL. Economic analysis: randomized, placebo-controlled clinical trial of dutasteride in men at high risk for prostate cancer. J Cancer Sci Ther. 2011;S3(004). doi: 10.4172/1948-5956.S3-004