Effects of sequential inductive systems with feeder cells from human aorta-gonad-mesonephros region, fetal liver and bone marrow on the differentiation of mouse embryonic stem cells into hematopoietic stem cells Chinese Journal of Tissue Engineering Research . 2011, (27): 4969 -4974 .  DOI: 10.3969/j.issn.1673-8225.2011.27.007