7Leung ASL, I.am TH, Hedley AJ, et al. Use of a subjective health measure on Chinese low back pain patients in Hong Kong. Spine,1999;24(10):961
8Ruta DA, Garratt AM, Wardlaw D, et al. Developing a valid and reliable measure of health outcome for patients with low back pain. Spine,1994,19(17):1 887