Hartz, Ingeborg, Aage Tverdal, and Svetlana Skurtveit. “A Comparison of Self-Reported Data on Disability Pension Status With Data from a Nationwide Administrative Register”. Norsk Epidemiologi 19, no. 2 (January 6, 2010). Accessed April 29, 2024. https://www.ntnu.no/ojs/index.php/norepid/article/view/587.