Ursin R, Holsten F, Bjorvatn B. Sleep in 40-45-year-olds in Hordaland county, Norway / Søvn hos 40-45 åringer i Hordaland. Nor J Epidemiol [Internet]. 2009Oct.9 [cited 2024Jul.5];16(2). Available from: https://www.ntnu.no/ojs/index.php/norepid/article/view/188