I have tried to identify this coin. I bought a lot of Chinese cash coins and this was identified as Chinese Northern Song cash coin. But this is not exactly similar as China Zhe Zong coins are, check for example Bao character. This also has some characters on reverse side. One of my friend suggest this could be Northern Vietnamese coin but I have not found similar from there either (Nguyen Huu Thong Bao). Can anyone of you help me?
Coin weight is 3.6 g and diameter 23.8 mm.