Reference
Barker : Page 236, Figure 103.2
Note:
Barker points out the frequent presence of excess metal in the central hole, indicative of the degradation of casting technology during this reign.
Reference
Thierry CMVS : CMVS, Page 81, numbers 461 and 462 [not illustrated]
Note:
Thierry (CMVS) indicates that the brass issues with plain reverse were of either 6 or 9 phần in weight. By its weight and size, this coin is the 9 phần issue.
