D. . Rink and M. . Wolff, “Housing Vacancy in Germany. On the Conceptualization of a Key Indicator for Housing Monitoring by Using Data from the German Housing Census (GWZ) 2011”, RuR, vol. 73, no. 5, pp. 311–325, Oct. 2015, doi: 10.1007/s13147-015-0361-8.