Sontirat, S., Jamonman, S. and Surinya, T. (1986) “The Influence of Psychological Factors on Agricultural Innovation of the Hill-Tribes of Northern Thailand”, Kasetsart Journal of Social Sciences, 7(2), pp. 75–85. available at: https://so04.tci-thaijo.org/index.php/kjss/article/view/243774 (accessed: 14 September 2026).