Reference
Note:
Greenbaum shows that a Tường Hữư Nguyên Bảo was illustrated in the Japanese work Wakan Kokon Senka Kagami dated 1798/99 by Masatsuna Kuchiki [Kutsuki] (1750-1802). He argues that this coin type was already known as early as the publication date of the Kecho Ruishu (circa 1681-83). The coin illustrated by Masatsuna may or may not be this actual specimen, depending on whether an undamaged specimen is present in the BM holding from his collection.