Pyy-Martikainen, Marjo, and Ulrich Rendtel. “Measurement Errors in Retrospective Reports of Event Histories. A Validation Study With Finnish Register Data”. Survey Research Methods 3, no. 3 (December 23, 2009): 139–155. Accessed July 25, 2024. https://ojs.ub.uni-konstanz.de/srm/article/view/2372.