Rusanen, J., T. Muilu, A. Colpaert, and A. Naukkarinen. “Georeferenced Data As a Tool for Monitoring the Concentration of Population in Finland in 1970–1998”. Fennia - International Journal of Geography, vol. 181, no. 2, Feb. 2003, pp. 129-44, https://fennia.journal.fi/article/view/3750.