Labor analgesia methods to improve labor outcome:a network meta ⁃analysis
MO Guohui, LIN Zhongyu⁃an, LIU Decheng, LIN Shiqing, ZHANG Hui, WANG Yimin
The Journal of Practical Medicine . 2020, (24): 3378 -3384 .  DOI: 10.3969/j.issn.1006⁃5725.2020.24.015