A multidimensional tool based on the ehealth literacy framework: development and initial validity testing of the ehealth literacy questionnaire (ehlq) L. Kayser, A. Karnoe, D. Furstrand, R. Batterham, K. Christensen, G. Elsworth, R. Osborne 2018 / Vol. 20, pp. 1 - 10 / Journal of medical internet research