Reference
Note:
HCR 58909, with its seal script legend, does not match any of the styles of Tường Nguyên Thông Bảo published by Thierry (CMV, CMVS) or by Hartill (GCC). However the general appearance of the coin seems to place it within Hartill’s extensive grouping of unofficial Zinc coins (GCC, pp 117-133). Hartill (p. 117) notes that these coins are often corroded (as in the case of HCR 58909). He quotes Thierry’s (CMVS, p. 58) dating for the zinc series: 1746-1774, by private mints under the Nguyên in the South of Vietnam, which has been tentatively adopted here.