Rattana Huangchumnong และผู้แต่งคนอื่นๆ. (2007) Comparison of the effects of sitting on a gym ball alone versus sitting on a gym ball with limb movements in the treatment of patients with chronic low back pain. Chulalongkorn University:ม.ป.ท.Rattana Huangchumnong และผู้แต่งคนอื่นๆ. 2007. Comparison of the effects of sitting on a gym ball alone versus sitting on a gym ball with limb movements in the treatment of patients with chronic low back pain. ม.ป.ท.:Chulalongkorn University;Rattana Huangchumnong และผู้แต่งคนอื่นๆ. Comparison of the effects of sitting on a gym ball alone versus sitting on a gym ball with limb movements in the treatment of patients with chronic low back pain. ม.ป.ท.:Chulalongkorn University, 2007. Print.