The first one is Cambodia 1973 100 riel paper money. On the front of the paper money are students in the classroom; On the back is the Angkor Wat Monument. Cambodian currency is not freely convertible in China, so Cambodian paper money cannot be exchanged in domestic banks. There is no exchange rate between Cambodian riel and RMB, so it should be converted by the exchange rate between Cambodian riel and US dollar. 100 cambodian riel is converted into 0. 14 RMB. The current price in the coin market is 4 yuan.

The second type is Yugoslav 1993 version of 100000 dinar banknotes. On the front of the banknote is Yugoslav writer ivo andric; On the back is the Yugoslav National Library. The Yugoslav dinar experienced hyperinflation during the period of 1990- 1994. This banknote was issued during this period (at that time, the maximum denomination of a single banknote in Yugoslavia reached 500 billion dinars), and now it has stopped circulating, so it cannot be exchanged. At present, the market price of coins is 10 yuan.

The third kind of paper money is not real money, but art paper money, which has no circulation value and is only for appreciation (the highest denomination of the euro is 500 euros). This artistic banknote was printed and sold by Naples Banknote Company in Italy in 2000 to commemorate the anniversary of the establishment of the Euro Single Currency Area 1. At present, the market price of coins is 80- 100 yuan.