1. https://www.parrot.com/us/drones. https://www.parrot.com/us/drones.
2. https://www.dji.com/. https://www.dji.com/.
3. https://www.ee.ucla.edu/mapping-air-pollution-from-a-drone/. https://www.ee.ucla.edu/mapping-air-pollution-from-a-drone/.
4. http://datafromsky.com/news/smart-parking-using-drones/. http://datafromsky.com/news/smart-parking-using-drones/.