RT Journal T1 How to appropriately choose research subjects A1 Liang-ping Hu, Xiao-lei Bao, Xue Guan, Qi Wang PB Journal of Integrative Medicine FD 2011-03-20 YR 2011 JF Journal of Integrative Medicine JO Journal of Integrative Medicine VO 9 IS 3 SP 242 DO 10.3736/jcim20110303 K1 ;statistics;medical;research design;research subjects LK {http://www.jcimjournal.com/EN/article/article_1586.shtml}