Takiguchi T, Yamaguchi S, Hashizume Y, et al: Movement of the Cauda Equina during the lateral decubitus position with fully flexed leg. Anesthesiology 101 : 1250, 2004
Pitkänen M : Spinal (subarachnoid) blockade. In Neural blockade. In clinical anesthesia and pain medicine. 4th ed., edited by Cousins MJ, Carr DB, Horlocker TT, et al, Wolters Kluwer/Lippincott Williams & Wilkins, Philadelphia, pp.213-240, 2009