Vassend, Olav, Benedicte Humborstad Orvik, Nikolai Olavi Czajkowski, and Espen Røysamb. “Facets of Neuroticism and Musculoskeletal Symptoms. A Study of Middle-Aged Twins”. Norsk Epidemiologi 26, no. 1-2 (July 20, 2016). Accessed May 1, 2024. https://www.ntnu.no/ojs/index.php/norepid/article/view/2015.