[https://www.wodumedia.com/chinese-diy-inventions/artist-matt-hope-wearing-a-helmet-pushes-his-air-filtration-bike-out-of-his-studio-on-a-hazy-day-in-beijing-on-march-26-2013-using-an-ikea-perforated-garbage-can-moped-helmet-fighter-pilot-brea/ air cleaning bike]
[https://www.youtube.com/watch?v=09BZ6ikBZ54 coal rollers] : militants anti-ecologistes