Feng, S. . “Study on Banknotes During the Reign of Rama IX of the Rattanakosin period in Thailand”. Nakhon Ratchasima Journal of Humanities and Social Sciences, vol. 1, no. 5, Oct. 2025, pp. 1-30, https://so11.tci-thaijo.org/index.php/NJHSS/article/view/2604.