Nunthasen, K., and W. Nunthasen. “Comparative Assessment of Health Cost and Costs and Returns Among Chemical Versus Organic Rice Cultivation Methods in Phayao Province”. Connexion: Journal of Humanities and Social Sciences, vol. 9, no. 1, June 2020, pp. 19-37, https://so05.tci-thaijo.org/index.php/MFUconnexion/article/view/243896.