Opsal, Anne, Øistein Kristensen, Torleif Ruud, Tor K. Larsen, Rolf W. Gråwe, and Thomas Clausen. “Substance Abuse in Patients Admitted Voluntarily and Involuntarily to Acute Psychiatric Wards: A National Cross-Sectional Study”. Norsk Epidemiologi 21, no. 1 (December 22, 2011). Accessed April 26, 2024. https://www.ntnu.no/ojs/index.php/norepid/article/view/1430.