Comparison of two ways to culture human primary first-trimester trophoblast cells 
Zhang Xiao-hong, Wang Hui-ling, Bai Jiang-tao, Li Yu-hong, Xu Qian
Chinese Journal of Tissue Engineering Research . 2012, (15): 2793 -2796 .  DOI: 10.3969/j.issn.1673-8225.2012.15.029