https://onlinelibrary.wiley.com/doi/abs/10.1002/j.2168-0159.2013.tb06364.x
https://www.spiedigitallibrary.org/conference-proceedings-of-spie/8648/1/Aerial-3D-LED-display-by-use-of-retroreflective-sheeting/10.1117/12.2005674.short?SSO=1
https://de.wikipedia.org/wiki/Retroreflektor
https://www.youtube.com/watch?v=zlN7DTx6urY