Hemrudee, Sunantinee, Auttapon Konburee, Jittapon Palakul, Saowanee Nakmareong, Wanida Donpunha, Ponlapat Yonglitthipagon, and Raoyrin Chanavirut. 2018. “A pilot study: Bed exercise with a modified bicycle ‘Pun Ngai’ in healthy volunteers”. Archives of Allied Health Sciences 30 (2). Khon Kaen, Thailand:216-25. https://he01.tci-thaijo.org/index.php/ams/article/view/145456.