The text is about the development of paper money. The Chinese used paper money, and bankers in Spain and Italy used bills of exchange. The Swedes are thought to be the first to use paper money in Europe. So, the missing word is: notes.

SCRIPTS

The Chinese were, as far as we know, the inventors of paper money and because it was so easy to move around compared with coins, it was named "flying money". They were also the first to experience an economic problem which has become all too familiar: by the 12^th century, there was enough money in circulation to cause serious inflation.

In Europe, it wasn't until about 1400 that bankers in Spain and Italy began to honor "bills of exchange", which were a kind of private paper money not in general use. They were documents used by those involved in a business transaction in which payment was made through a third party to avoid the cost of foreign exchange. However, it is the Swedes who are generally credited with producing the first proper European bank [BEEP].