Reference
Note:
In his published survey of Vietnamese coins in the HCR collection Thierry identified this coin type as a Northern Vietnamese copy of Zhou Yuan Tong Bao (Thierry 2012a, page 42, Figure 14). There are two different examples of this coin type from the collection of Kutsuki Masatsuna with the same ticket reference code: I. c i (added by E.T. Leeds), HCR 99698 (this coin) and HCR 99701 (the figured coin in Thierry 2012a, Fig. 14).