Efficacy,Problems and Current Status of Two-way Referral from 1997 to 2017 in China:a Systematic Review 
SHEN Ying,HUANG Weiran,JI Shuyu,YU Jia,LI Mujun
Chinese General Practice . 2018, (29): 3604 -3610 .  DOI: 10.12114/j.issn.1007-9572.2018.00.033