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
Aguado J, Campbell A, Ascaso C, Navarro P, Garcia-Esteve L, Luciano JV. Examining the factor structure and discriminant validity of the 12-Item General Health Questionnaire (GHQ-12) among Spanish postpartum women. Assessment. 2012 Dec 19;19(4):517-25.
Jeuland M, Maskery B, Cook J, Poulos C, Clemens J, Lauria D, Stewart J, Lucas M, Whittington D. Incorporating cholera vaccine herd protection into economic cost-benefit and cost-effectiveness models. Procedia Vaccinol. 2010;2(2010):140-6. doi: 10.1016/j.provac.2010.07.006