Πηγές-Μέσα
https://www.ecowatch.com/top-10-greenest-cities-in-the-world-1881963132.html
https://www.gvi.co.uk/blog/top-5-green-cities-world-2016/
https://themysteriousworld.com/10-greenest-cities-around-the-world/
https://matadornetwork.com/read/the-10-greenest-cities-in-the-world/
