โทนรัตน์ ณ. การศึกษาตามอัธยาศัย. Journal of Education Studies, Chulalongkorn University, Bangkok, Thailand, v. 47, n. 3, p. 568, 2019. Disponível em: https://so02.tci-thaijo.org/index.php/EDUCU/article/view/218924. Acesso em: 30 sep. 2026.