TY - JOUR AU - Qu, B. AU - Chen, L. AU - Zhang, Y. PY - 2020 DA - 2020// TI - Landmark-guided versus modified ultrasound-assisted Paramedian techniques in combined spinal-epidural anesthesia for elderly patients with hip fractures: a randomized controlled trial JO - BMC Anesthesiol VL - 20 UR - https://doi.org/10.1186/s12871-020-01172-x DO - 10.1186/s12871-020-01172-x ID - Qu2020 ER -