collapse.png - Deutsches Bundesarchiv (CC-BY-SA 3.0)
maglev.png - Saruno Hirobano (CC-BY-SA 4.0)
highfactory.png - Cards84664 (CC-BY-SA 4.0)
ravenfield.png - Colin (CC-BY-SA 4.0)
elvon.png - IqRS (public domain)
protest.png - VargaA (CC-BY-SA 4.0), modified by Valixor