Sinturat, Thitapa, Krishna Kosashunhanan, Aram Iamlaor, Kongkiat Khunasathitchai, และ Nikorn Teptong. 2022. “English Speaking Problems of Engineering Students: A Case Study of Rajamangala University of Technology Thanyaburi”. Journal of Roi Kaensarn Academi 7 (5):1-9. https://so02.tci-thaijo.org/index.php/JRKSA/article/view/256034.