Brakel, Jan van den. “Sampling and Estimation Techniques for the Implementation of New Classification Systems: The Change-over from NACE Rev. 1.1 to NACE Rev. 2 in Business Surveys”. Survey Research Methods 4, no. 2 (September 11, 2010): 103-119. Accessed June 15, 2021. https://ojs.ub.uni-konstanz.de/srm/article/view/2354.