Wang, Yu, et al. “Halo-Pelvic Traction for Extreme Lumbar Kyphosis: 3 Rare Cases With a Completely Folded Lumbar Spine”. Acta Orthopaedica, vol. 92, no. 1, Sept. 2020, pp. 9-14, doi:10.1080/17453674.2020.1824170.