Nantapak, Banluesak, Jidapa Pronying, and Korakod Tongkachok. 2023. “A New Approach to Determine the Age of Emancipation in the Modern Era”. Rajapark Journal 17 (52). Bangkok, Thailand:1-18. https://so05.tci-thaijo.org/index.php/RJPJ/article/view/261200.