Effect of cell density on differentiation of bone marrow mesenchymal stem cells into neuronal-like cells 
Ke Jun-long, Xu Zhi-en, Li Hua, Chen Jing-juan, Liang Wei
Chinese Journal of Tissue Engineering Research . 2010, (32): 5908 -5912 .  DOI: 10.3969/j.issn.1673-8225.2010.32.004