Meyer, B. et al. 1999. Tertiarisation without a competitive industrial base? An empirical analysis of shifts in the sectoral structure of employment in the münsterland and in the emscher-lippe region. Raumforschung und Raumordnung | Spatial Research and Planning. 57, 5-6 (Sep. 1999), 386–397. DOI:https://doi.org/10.1007/BF03184507.