Ritthong ปิยพร, Rattanapan กนกรัตน์, Jitpukdee สุวิทย์, and Muneenam อุมาพร. 2021. “Development of Ability in Natural Resources and Environmental Protection Volunteers in Phatthalung Province”. Journal of Vocational Institute of Agriculture 5 (1):49-60. https://li01.tci-thaijo.org/index.php/JVIA/article/view/249328.