Very interesting. Under the section on the Middle Ages, there's a brief reference to the Chinese adopting paper money and such; does anyone happen to have a go

Very interesting. Under the section on the Middle Ages, there's a brief reference to the Chinese adopting paper money and such; does anyone happen to have a good resource for learning more about this period? It's always interesting to go back and look at such a drastic shift, as I'm assuming that likely was.