Effect of dualinjection on coracoid approach brachial plexus block guided by nerve stimulator：compared with singleinjection 
HE Wensheng1, ZU Lingjie2, YANG Xiaochun1*, SUN Haijun1, WU Zhenyu1
Journal of Hebei Medical University . 2019, (2): 193 -197 .  DOI: 10.3969/j.issn.10073205.2019.02.018