Experience: I crossed the Alps on a space hopper | Life and style | The Guardian
https://www.theguardian.com/lifeandstyle/2018/sep/14/i-crossed-alps-on-a-space-hopper-experience
https://www.theguardian.com/lifeandstyle/2018/sep/14/i-crossed-alps-on-a-space-hopper-experience
https://www.deutschlandfunknova.de/beitrag/fortschritt-abneigung-gegenueber-neuem
https://dzone.com/articles/a-simplest-block-chain-in-java