Falkenberg, H. K., Johansen, T. R., & Thorud, H.-M. S. (2020). Headache, eyestrain, and musculoskeletal symptoms in relation to smartphone and tablet use in healthy adolescents . Scandinavian Journal of Optometry and Visual Science, 13(2), 8–14. https://doi.org/10.5384/sjovs.vol13i2p8-14