Headache, tinnitus and hearing loss in the international Cohort Study of Mobile Phone Use and Health (COSMOS) in Sweden and Finland - Auvinen, A; Feychting, M; Ahlbom, A; Hillert, L; Elliott, P; Schuz, J; Kromhout, H; Toledano, MB; Johansen, C; Poulsen, AH; Vermeulen, R; Heinavaara, S; et al. (International Journal of Epidemiology, 2019)