Getting Started in Primary Care Research:Choosing among Six Practical Research Approaches 
Michael D Fetters(writing),ZHANG Yanan(translator),HAN Jianjun,XU Yanli,YANG Hui(reviser)
Chinese General Practice . 2019, (22): 2653 -2659 .  DOI: 10.12114/j.issn.1007-9572.2019.00.396