Granato, Nadia, Anette Haas, Silke Hamann, and Annekatrin Niebuhr. 2009. “Labour Mobility in Germany — Regional Migration and Commuting Distinguished Between Different Educational Levels”. Raumforschung Und Raumordnung | Spatial Research and Planning 67 (1): 21–33. https://doi.org/10.1007/BF03183140.