1. https://pixabay.com/illustrations/background‐pattern‐brain‐face‐5127760/. Pictures taken from pixabay Stunning free images & royalty free stock
2. https://wallpaperaccess.com/the‐flintstonesPictures taken from free images & royalty free stock
3. https://www.un.org/en/development/desa/population/publications/pdf/trends/Population2030.pdf
4. Photo courtesy of Brandweer Nederland https://zerauto.nl/achtergrond‐daarom‐plaatst‐de‐brandweer‐sommige‐autos‐in‐een‐waterbak/
5. Photo courtesy of Bike Europe https://www.bike‐eu.com/home/nieuws/2018/02/underrated‐e‐bike‐battery‐fire‐hazards‐call‐for‐attention‐on‐safe‐storage‐10132804