Hak, Tony, Kees van der Veer, and Harrie Jansen. “The Three-Step Test-Interview (TSTI): An Observation-Based Method for Pretesting Self-Completion Questionnaires”. Survey Research Methods 2, no. 3 (December 19, 2008): 143–150. Accessed November 6, 2024. https://ojs.ub.uni-konstanz.de/srm/article/view/1669.