Optimum spinal anesthesia dose of ropivacaine combined with a single low-dose S-ketamine during elective cesarean delivery: a double-blind sequential study
SUN Yuanqing, XU Tao, ZHANG Xiaoyu, XU Zifeng, CHAI Jing
Journal of Shanghai Jiao Tong University (Medical Science) . 0, (): 90 -96 .