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
Grogan S, Hartley L, Fry G, Conner M, Gough B. Appearance concerns and smoking in young men and women: going beyond weight control. Drug-Educ Prev Polic. 2010 May 6;17(3):261-9. doi: 10.3109/09687630802422019
Brodtkorb T, Kogler GF, Arndt A. The influence of metatarsal support height and longitudinal axis position on plantar foot loading. Clin Biomech (Bristol, Avon). 2008;23(5):640-7.