1. Smart Cities: Definitions, Dimensions, Performance, and Initiatives
2. https://www.unfpa.org/ [accessed in January 2020].
3. https://ec.europa.eu/eurostat/databrowser/view/tps00001/default/table?lang=en [accessed in January 2020].
4. https://ec.europa.eu/eurostat/statisticsexplained/index.php?title=File:Distribution_of_population_,_2011_-_%25,_V2.png [accessed in January 2020].
5. https://ec.europa.eu/eurostat/statistics-explained/index.php/Archive:Urbanrural_typology_update [accessed in January 2020].