Vandenplas, Caroline, Dominique Joye, Michèle Staehli, and Alexandre Pollien. 2015. “Identifying Pertinent Variables for Nonresponse Follow-Up Surveys. Lessons Learned from 4 Cases in Switzerland”. Survey Research Methods 9 (3), 141-58. https://doi.org/10.18148/srm/2015.v9i3.6138.