Greiving, S. , Flex, F. and Terfrüchte, T. (2015) “Comparative Study on the Central Place Concepts of the GermanLänder and Recommendations for their Further Development”, Raumforschung und Raumordnung | Spatial Research and Planning, 73(4), pp. 285–297. doi:10.1007/s13147-015-0357-4.