Meksangsouy, P., S. Nipithwittaya, and C. Losiri. “Guidelines for Fieldwork Activities in Environmental Geography: : A Case Study of the East of Thailand”. Journal of Letters, Vol. 49, no. 1, June 2020, pp. 146-61, https://so03.tci-thaijo.org/index.php/jletters/article/view/240839.