Pingkaew, Natthineeporn, Chomponuch Jittithavorn, Chawalee Na Talang, and Kannapa Pongponrat. 2020. “Behaviors, Experiences, and Needs of Senior Tourists Visiting Khao Yai National Park”. Dusit Thani College Journal 14 (3):51-77. https://so01.tci-thaijo.org/index.php/journaldtc/article/view/245492.