1. United Nations Department of Economic and Social Affairs. World Urbanization Prospects 2018: Highlights, ST/ESA/SER.A/421, 2018.;
2. ITU-T Focus Group on Smart Sustainable Cities. Smart sustainable cities: an analysis of definitions, FG-SSC Technical report, ITU, Geneva, 2014.;
3. European Parliament. Mapping smart cities in the EU, Study, available at: https://www.europarl.europa.eu/committees/en/supporting-analyses-search.html, 2014.;
4. Berrone P. et al. New York edges out London as the world's smartest city, IESE insight review. 2016.;
5. Aleksić S, A survey on optical technologies for IoT, smart industry and smart infrastructures, Journal of Sensor and Actuator networks, Vol. 8, No. 47, pp. 1-18, 2019.;